MikaStars39/nano-eval huggingface dataset:
The common yarn characteristic number and density of woven fabrics represent a fabric in a certain writing way, if the warp characteristic number of the fabric is 28tex and the weft characteristic number is 32tex; The warp density is 240 pieces /10cm, the weft density is 200 pieces /10cm; Its representation is ().

Options:
A. 28x32x240x220
B. 28x32x240x210
C. 28x32x200x240
D. 32x30x240x200
E. 28x32x240x200
F. 32x28x200x240
G. 32x28x240x200
H. 28x30x240x200
I. 28x32x210x200
J. 28x32x230x200
Answer: E
The diameter of textile fibers is generally in ().

Options:
A. Millimeter-level
B. Nanometer-level
C. inch-level
D. Micron-grade
E. Inch-level
F. Centimeter-level
G. Pico-level
H. Kilometer-level
I. Meter level
J. Nanometer scale
Answer: D
How does the friction coefficient of fibers change with the increase of the relative motion speed between fibers?

Options:
A. Increase first, then decrease.
B. First reduce, then stabilize
C. First maintain, then reduce.
D. First reduce, then increase.
E. Increase
F. First increase, then remain unchanged.
G. First increase, then expand.
H. First reduce, then decrease
I. First maintain, then increase
J. Reduce
Answer: D
In order to avoid the decomposition of anthraquinone due to excessively high temperatures, fuming sulfuric acid is generally used for the sulfonation of anthraquinone. When sulfonated, sulfonation reactions tend to occur on the () benzene rings.

Options:
A. 3
B. 9
C. 5
D. 4
E. 2
F. 8
G. 6
H. 7
I. 10
J. 1
Answer: E
The reaction of sodium salts of phenolic compounds with carbon dioxide to introduce a carboxyl group on the () is called the Kaulpe reaction.

Options:
A. nucleic base
B. ammonia molecule
C. carbonyl group
D. heterocyclic core
E. alkyl chain
F. aryl ring
G. alkene group
H. benzene ring
I. aromatic hydroxyl
J. fatty acid
Answer: F
The main performance indicators to measure the performance of reactive dyestuffs are (), diffusivity, color fixation rate, safety and so on.

Options:
A. transparency
B. brightness
C. durability
D. conductivity
E. density
F. malleability
G. viscosity
H. flammability
I. odor
J. solubility
Answer: J
The coupling reaction is an aromatic electrophilic substitution reaction, so the coupling activity is high when the diazonium salt has a ____ on the aromatic nucleus.

Options:
A. non-reactive side chain
B. electron-withdrawing substituent
C. charged alkyl group
D. hydrophobic side chain
E. electron-neutral substituent
F. small hydrocarbon ring
G. nonpolar functional group
H. electron-absorbing substituent
I. electron-donating substituent
J. polar side molecule
Answer: B
There is a continuously operating rotary vacuum filter, whose production capacity is expressed in (m³ filtrate/h). The amount of filtrate obtained per rotation is expressed as V(m³). If the resistance of the filtering medium can be ignored, which of the following options is correct when the rotational speed of the drum is increased?

Options:
A. V decreases, Q increases
B. V increases, Q remains constant
C. V remains constant, Q decreases
D. V decreases, Q remains constant
E. Q remains constant, V decreases
F. V increases, Q increases
G. Q remains constant, V increases
H. V decrease, Q decrease
I. V increases, Q decreases
J. V remains constant, Q remains constant
Answer: A
What primarily determines the height of the mass transfer unit?

Options:
A. Gas flow rate, packing characteristics, system properties
B. Liquid density, gas pressure, system capacity
C. System pressure, column diameter, liquid properties
D. Gas temperature, column material, flow dynamics
E. System operation time, gas viscosity, packing density
F. Flow pattern, system design, packing arrangement
G. Column height, liquid flow rate, packing type
H. Gas velocity, system efficiency, material conductivity
I. Packing size, system temperature, gas composition
J. Liquid viscosity, packing material, temperature variations
Answer: A
Elevating the gas temperature can make the production capacity of the dust reduction chamber ( ) due to ( ).

Options:
A. Increase, decrease in pressure differential
B. Remain stable, decrease in gas viscosity and increase in settling velocity
C. Decrease, decrease in gas viscosity and increase in pressure differential
D. Decrease, increase in gas pressure and decrease in gas velocity
E. Increase, increase in gas viscosity and decrease in gas pressure
F. Decrease, increase in gas viscosity and decrease in settling velocity
G. Increase, increase in gas pressure and decrease in settling velocity
H. Remain stable, modification in gas density and turbulence enhancement
I. Decrease, decrease in gas pressure and increase in settling velocity
J. Increase, decrease in gas viscosity and increase in settling velocity
Answer: F
In drying operation, multi-stage or intermediate heating is suitable for drying of () materials, and partial exhaust gas circulation is suitable for drying of () materials.

Options:
A. High heat capacity, prolonged heating; Prone to microbial growth, contamination (sanitization control)
B. Durable construction materials, structural stability; Organic materials, biode
C. Elastic materials, tensile flexibility; Susceptible to brittleness, micro-cracks (stress control)
D. Cannot withstand high temperatures, heat sensitivity; Prone to warping, cracking (internal migration control)
E. Low melting point, thermal fragility; Vulnerable to thermal stress, deformation (expansion control)
F. High thermal resistance, heat insensitivity; Prone to chemical reactions, oxidation (external migration control)
G. Low thermal conductivity, slow heat transfer; High oil content, rapid spoilage
H. Hygroscopic, moisture retention; Volatile compounds, aroma preservation
I. Soft texture, compressibility; Prone to sponginess, water uptake (moisture control)
J. Sensitive to UV rays, light degradation; Prone to mold, fungal growth (hygroscopic control)
Answer: D
A set of tube heat exchanger with longitudinal fins on the outside of the inner tube. In this heat exchanger, water is used to cool the air, which should go () (between the inner tubes or the shells between the inner and outer tubes) and water () (between the inner tubes or the shells between the inner and outer tubes).

Options:
A. through the outer tubes, the inner shells
B. between the inner and outer tubes, inner tube
C. inner tube, the shells between the inner and outer tubes
D. between the inner and outer tubes, the shells
E. the shells between the inner and outer tube,inner tube
F. the inner tubes, between the outer and inner tubes
G. the shells, between the inner and outer tubes
H. the inner tubes, the shells between the inner and outer tube
I. the outer tube, the shells between the inner and outer tube
J. the outer tubes, between the inner and outer shells
Answer: E
Under certain dry conditions, as the thickness of the material increases, the critical moisture content of the material will (), while the time required for drying will ().

Options:
A. Reduce, maintain
B. Maintain, reduce
C. Decrease, extend
D. Expand, prolong
E. Decrease, decrease
F. Increase, extend
G. Increase, reduce
H. Reduce, increase
I. Extend, reduce
J. Maintain, extend
Answer: F
A fluid with a constant flow rate passes through a pipe with a square cross-section (side lengths), now if the side lengths are doubled, the Reynolds number of the fluid flow becomes a multiple of the original?

Options:
A. 3/4
B. 3/2
C. 1/4
D. 1/8
E. 4
F. 2
G. 5/4
H. 8
I. 16
J. 1/2
Answer: J
The equilibrium moisture content of the material must be ().

Options:
A. bound moisture
B. total moisture level
C. absolute water quantity
D. critical moisture content
E. fixed hydration level
F. free moisture
G. unbound water
H. essential water proportion
I. variable water content
J. constant moisture ratio
Answer: A
What is the level H of an open tank, the outside air pressure Pn, and the diameter of the bottom outlet pipe d. When λ ≠ 0, what is the velocity u of the outlet water related to?

Options:
A. Influenced by both Pn and d
B. Dependent solely on H
C. Governed by λ alone
D. Influenced only by Pn
E. Outlet pipe diameter d
F. Determined by Pn and λ
G. Concerned with H and Pn
H. Liquid Level H
I. Related to both H and d
J. External atmospheric pressure Pn
Answer: I
The process of glycogen being broken down into glucose in the liver is called_______.

Options:
A. glycosecretion
B. glucogenesis
C. glycogenic
D. gluconeogenesis
E. glycogenolysis
F. glucose synthesis
G. glycogen synthesis
H. glucolysis
I. glycogenesis
J. glycolysis
Answer: E
_________ acid is a derivative of trienoic, tetraenoic, and pentaenoic acids from peanuts.

Options:
A. Gamma-linolenic
B. Docosahexaenoic
C. Linolenic
D. Arachidonic
E. Palmitoleic
F. Stearic
G. Oleic
H. Docosapentaenoic
I. Eicosapentaenoic
J. Linoleic
Answer: D
______refer to lipids other than fats, primarily including phospholipids, glycolipids, and sterols.

Options:
A. Lipoids
B. Liparins
C. Glycoproteins
D. Phosphatids
E. Sterolases
F. Lipases
G. Carbolipids
H. Steroids
I. Glycogens
J. Glycoloids
Answer: A
The essential function of uncoupling agents is to disrupt the _____across the mitochondrial inner membrane. Uncoupling agents do not affect electron transfer and oxygen consumption, but they do not generate ATP.

Options:
A. oxygen equipoise
B. calcium exchange
C. glucose concentration
D. lipid barrier
E. carbon dioxide level
F. water flow
G. enzyme alignment
H. proton gradient
I. potassium balance
J. sodium channel
Answer: H
A nucleotide is composed of a ___ and a _____ group.

Options:
A. base pair, sulfur
B. nucleotide, sulfur
C. enzyme, lipid
D. base unit, sugar
E. amino acid, peptide
F. enzyme, carbohydrate
G. nucleoside, phosphate
H. nucleoside, carboxyl
I. ribosome, phosphate
J. nucleotide, amino
Answer: G
______refer to a type of lipid containing phosphate groups in their molecules, including glycerophospholipids and sphingomyelins, which are the main components of biological membranes.

Options:
A. Ester lipids
B. Nucleolipids
C. Fatty acids
D. Cholesterol
E. Glycolipids
F. Steroids
G. Phospholipids
H. Triglycerides
I. Peptidolipids
J. Lipoproteins
Answer: G
_____refers to the process where amino acids undergo oxidative dehydrogenation and hydrolytic deamination catalyzed by enzymes, resulting in the formation of ammonia and α-keto acids.

Options:
A. Enzymatic decarboxylation
B. Reductive dehydrogenation
C. Hydrolytic decarboxylation
D. Oxidative deamination
E. Aerobic deamination
F. Aerobic glycolysis
G. Hydrolytic deamination
H. Reductive amination
I. Oxidative phosphorylation
J. Oxidative decarboxylation
Answer: D
When a high concentration of neutral salts is added to a protein solution, the inorganic salt ions snatch water molecules from the hydration shell of the protein molecules, disrupting the shell and causing the protein molecules to combine with each other and precipitate. This phenomenon named _____

Options:
A. salting-out
B. hydration disruption
C. salting-in
D. ion exchange
E. coagulation point
F. salting-over
G. molecular binding
H. water transfer
I. salt bridging
J. ion snatch
Answer: A
When the traffic is about to enter the bottleneck, it generates a wave in the opposite direction, like the reflection of sound waves against an obstacle or the backrush when the flow of water in a pipe is suddenly blocked. This wave causes turbulence in the traffic flow on the road section before the bottleneck, what is this called?

Options:
A. Vehicle movement slows
B. Traffic jam intensifies
C. Traffic density multiplies
D. Vehicle volume expands
E. Road blockage worsens
F. Vehicle speed decreases
G. Traffic flow fluctuates
H. Traffic surge increases
I. Road congestion escalates
J. Road capacity lessens
Answer: G
In one cycle, all vehicles arriving at the intersection are precisely allowed to pass without any remaining and without any extra signal cycle time, what is this called?

Options:
A. The coordinated signal period.
B. The balanced traffic flow.
C. The optimal cycle length.
D. The minimum signal cycle.
E. The traffic flow equilibrium.
F. The congestion clearance rate.
G. The synchronized passage cycle.
H. The residual signal time.
I. The maximum signal duration.
J. The intersection pass-through time.
Answer: D
When solving transportation problems, if the improvement routes and check numbers for each cell have been obtained, what principle governs the selection of the adjustment cell?

Options:
A. Among all routes, the one selected to adjust is the cell with a positive but lowest check
B. Among all cells, the one selected as the adjustment cell is the one with the lowest and negative check
C. Among all routes, the choice for the adjustment cell is the one with the most relative need
D. Among all cells, the option elected for adjustment is that with a moderate and highest check
E. Among all cells, the one chosen as the adjustment cell is the one with a negative but highest check
F. Among all cells, the one chosen as the balance cell is the one with a positive and highest check
G. Among all cells, the one chosen as the adjustment cell is the one with a positive but lowest check
H. Among all cells, the one chosen as the routing cell is one with a moderate and zero check
I. Among all routes, the one selected as the adjustment cell is the one with a positive and lowest check
J. Among all cells, the one chosen as the adjustment cell is the one with a positive and highest check
Answer: J
With the development of science and technology, subway technology is also showing a diversified development trend at present, including (), () and ().

Options:
A. Swift subway, slow-paced subway, little subway
B. Accelerated subway, usual subway, petite subway
C. Heavy subway, light subway, micro subway
D. Dense subway, featherlight subway, micro subway
E. Express subway, regular subway, tiny subway
F. Speedy subway, leisurely subway, miniaturized subway
G. Fast subway, efficient subway, compact subway
H. Urban subway, rural subway, nano subway
I. Quick subway, standard subway, small subway
J. Rapid subway, slow subway, mini subway
Answer: C
Special goods transport product series, that is, freight products developed for goods with special needs, mainly fresh goods transport products, dangerous goods transport products and ().

Options:
A. Over-limit cargo transport products
B. Over-standard cargo transport products
C. Oversized package transport products
D. Extreme-condition cargo transport products
E. Over-capacity cargo transport products
F. High-demand cargo transport products
G. High-altitude cargo transport products
H. Underweight cargo transport products
I. Over-the-border cargo transport products
J. Over-speed cargo transport products
Answer: A
() is to make reasonable arrangements for the configuration and stacking of goods on the means of transport. The result is ().

Options:
A. Distribution, organization of logistical operations
B. Assembly, arrangement of item assembly sequences
C. Loading, mapping out placement locations
D. Segregation, setup of segregation procedures
E. Stowage, preparation of planning stowage plan
F. Handling, determination of equipment needs
G. Containerization, formation of packing guidelines
H. Consolidation, execution of consolidation protocols
I. Packaging, development of a protection scheme
J. Storage, creation of cargo sorting strategy
Answer: E
The transportation process mainly includes two parts: the transportation business process between the transportation user and the transportation enterprise and ().

Options:
A. Transit company transport system of relocating passengers and freight
B. Transport business transport process of transferring passengers and cargo
C. Aviation enterprise transport process of dispatching passengers and goods
D. Transport enterprise shipment procedure of carrying passengers and goods
E. Transportation company movement method of ferrying customers and products
F. Transport enterprise transport procedure of moving passengers and freight
G. Transport enterprise transport process of transporting passengers and goods
H. Carrier business transport operations of conveying individuals and cargo
I. Logistics organization transport mechanism of shifting people and merchandise
J. Cargo carrier transport process of handling passengers and commodities
Answer: G
The unique functions of the transportation system mainly include (), (), () and ().

Options:
A. Manufacturing function, mobility service function, trading function, civil protection function.
B. Fabrication function, people movement function, distribution activity function, country defense
C. Supply function, person movement function, commerce function, public defense function.
D. Industrial function, passenger mobility function, exchange function, defense utility.
E. Production function, passenger transport function, circulation function, national defense function.
F. Build function, passenger mobility function, trading operation function, civic protection function.
G. Production function, passenger service function, distribution function, public safety function.
H. Assembly function, human transport function, market flow function, defense coverage function.
I. Production role, traveler support function, distribution role, homeland security function.
J. Utility function, people transport function, market function, military function.
Answer: E
The indicators for assessing the work of civil aviation transport mainly include (), (), flight safety indicators and labor productivity indicators.

Options:
A. Logistics efficiency, regional connectivity index
B. Fare competitiveness, route network coverage
C. Air traffic volume, technology upgrade rate
D. Passenger load factor, service quality index
E. Transportation capacity, operational reliability index
F. Customer satisfaction scores, maintenance efficiency
G. Output index, technical and economic index
H. Cargo handling speed, market penetration metrics
I. Aircraft utilization coefficient, fuel consumption rate
J. Ticketing system effectiveness, regional development scale
Answer: G
In the transaction activities of the transport market, (), () and () are directly engaged in the exchange of passenger and cargo transport and act as actors in the transport market.

Options:
A. Observer, supplier, and helper
B. Consumer, distributor, and facilitator
C. Passenger, carrier, and agent
D. Shipper, receiver, and negotiator
E. Customer, provider, and broker
F. Buyer, seller, and agent
G. Demander, supplier and intermediary
H. Purchaser, transporter, and coordinator
I. Trader, handler, and representative
J. User, deliverer, and middleman
Answer: G
The characteristics of cargo transport are (), (), () and ().

Options:
A. The universality of objects, the timeliness of transportation, directionality of transportation, the complexity of transportation organization
B. The uniformity of objects, the permanence of transportation, the variability of transportation, the simplicity of transportation organization
C. The variability of objects, the permanence of transportation, the specificity of transportation, the simplicity of transportation organization
D. The consistency of objects, the frequency of transportation, specificity of transportation, the simplicity of transportation organization
E. The variation of objects, the constancy of transportation, randomness of transportation, the flexibility of transportation organization
F. The multiplicity of objects, the reliability of transportation, the predictability of transportation, the adaptability
G. The diversity of objects, the urgency of transportation, the randomness of transportation, the rigidity of transportation organization
H. The rarity of objects, the urgency of transportation, the consistency of transportation, the rigidity of transportation organization
I. The uniformity of objects, the immediacy of transportation, the uniformity of transportation, the flexibility of transportation organization
J. The disparity of objects, the promptness of transportation, linearity of transportation, the stiffness of transportation organization
Answer: A
When transporting goods liable to contaminate other goods by rail, if the quantity is less than one carload, it shall be ().

Options:
A. Container delivery
B. Single shipment
C. Freight bundling
D. Individual shipping
E. Car allocation
F. Train dispatch
G. Car consignment
H. Rail distribution
I. Vehicle transfer
J. Box packaging
Answer: G
Generally, in energy and heavy industry bases with large freight demand, because transport demand is heavily dependent on relatively fixed transport modes and routes, the lower the degree of price sensitivity, the demand elasticity will be (); The more dispersed the goods with less load, the more sensitive they are to price, and the elasticity of demand will be ().

Options:
A. less, more
B. lesser, fewer
C. bigger, smaller
D. smaller, bigger
E. higher, lower
F. stable, variable
G. greater, smaller
H. similar, different
I. stronger, weaker
J. reduced, increased
Answer: D
Cargo consignment specifically includes (), (), () and other work links.

Options:
A. Labeling; To mark packages; And identify contents
B. Allocation; To allocate for transport; And audit products
C. Dispatch; To send out shipments; And coordinate deliveries
D. Inspection; To check for damages; And ensure quality
E. Scheduling; To plan routes; And estimate arrival
F. Packing; To verify contents; And seal containers
G. Inventory; To log items; And monitor quantities
H. Warehousing; To store items; And maintain inventory
I. Consignment; To accept for carriage; And inspect goods
J. Documentation; To prepare for shipping; And organize transport
Answer: I
According to the highway engineering technical standards, the bearing standards of highway Bridges are divided into three types: (), () and ()

Options:
A. Structural weight; Supported weight; Tension weight
B. Carriage stress; Freight burden; Axle pressure
C. Heavy load; Light load; Medium load
D. Passenger vehicles; Transport trucks; Motorcycles
E. Narrow bridge; Wide bridge; Adjustable bridge
F. Vehicle weight; Utility vehicle; Cargo capacity
G. Type A roads; Type B roads; Type C roads
H. Light cars; Heavy cars; Balanced cars
I. Highway capacity; Bridge width; Traffic flow
J. Car load; Flatbed car; Crawler load
Answer: J
According to the characteristics of vehicle operation and different requirements for loading and unloading organization, towed transport can be divided into () transport and () transport, of which () transport is the main form of towed transport in our country.

Options:
A. Push into; Semi-fixed mount; Semi-fixed mount
B. Slide in; Permanent attach; Permanent attach
C. Lift up; Modular suspension; Modular suspension
D. Swing load; Integrated linkage; Integrated linkage
E. Hang up; Fixed suspension; Fixed suspension
F. Clamp on; Dynamic clasp; Dynamic clasp
G. Roll on; Static hookup; Static hookup
H. Pull out; Temporary hook; Temporary hook
I. Hook lift; Loose hanging; Loose hanging
J. Drop off; Manual linkage; Manual linkage
Answer: E
The motor transport production plan consists of four parts: (), (), () and ().

Options:
A. Traffic volume plan; Vehicle planning; Vehicle operation plan; Vehicle operation plan
B. Vehicle arrangement chart; Driver scheduling; Traffic control system; Repair scheduling
C. Route progress chart; Vehicle allocation; Driving conditions plan; Service maintenance log
D. Traffic control strategy; Garage management; Route scheduling; Maintenance scheduling
E. Vehicle control system; Fleet distribution; Route management plan; Maintenance timetable
F. Traffic implementation chart; Garage setup; Vehicle coordination; Repair plan
G. Traffic management setup; Garage plan; Route coordination; Service timing
H. Vehicle acquisition setup; Driving personnel plan; Traffic analysis; Repair timetable
I. Road capacity strategy; Transport planning; Operational vehicle scheme; Operational vehicle scheme
J. Transportation scheme; Fleet organization; Road usage strategy; Vehicle upkeep schedule
Answer: A
The transportation cost range of road transport enterprises is divided into two categories according to its use: () and ().

Options:
A. Repair benefits; Administrative costs
B. Road bills; Staff payments
C. Travel fees; Organizational costs
D. Vehicle expenses; Enterprise management fee
E. Maintenance costs; Administrative expenses
F. Insurance premiums; Management salaries
G. Vehicle wear; Coordination fees
H. Road taxes; Operational charges
I. Fuel charges; Employee salaries
J. Driving rates; Company expenses
Answer: D
When scheduling shifts, consider (), (), () and ().

Options:
A. Vehicle maintenance timing, passenger location at midpoint, required driver breaks, station operation logistics.
B. Vehicle operation speed, passenger partial accommodation locale, driver time off, possible station operation statuses.
C. Vehicle operation time, passenger halfway accommodation location, driver rest and rest time, relevant station operation arrangements.
D. Vehicle fuel levels, passenger comfort preferences, driver schedules alignment, strategic station positioning.
E. Vehicle operation capacity, passenger total accommodation needs, driver available hours, nearby station functionalities.
F. Vehicle maintenance requirements, passenger halfway accommodation location, driver rest and rest time, relevant station operation arrangements.
G. Vehicle operation rate, traveler halfway stop preferences, driver sleep hours, important station management plans.
H. Vehicle operational intervals, halfway accommodation for passengers, resting periods for drivers, managing station operations.
I. Vehicle operation pace, passenger end-to-end accommodation location, driver rest and rest time, relevant station operation arrangements.
J. Vehicle operation periods, passenger halfway resting spots, driver break schedules, essential station operation tactics.
Answer: C
The basic production unit of railway transport is ().

Options:
A. Train loading segment
B. Railway station section
C. Railway signaling area
D. Train dispatching line
E. Train operation sector
F. Railway maintenance zone
G. Railway management unit
H. Railway control division
I. Train service department
J. Train navigation network
Answer: B
The force acting on a rigid body is ().

Options:
A. Directional constant
B. Movement scalar
C. Rotate the vector
D. Slide vector
E. Bidirectional vector
F. Torsion coefficient
G. Rotation parameter
H. Pivot quantity
I. Positioning vector
J. Shift factor
Answer: D
What can be used as a substitute for ZChSnSb11-6 alloy for low-speed diesel engine main bearings?

Options:
A. 35 high tin aluminum alloy
B. 40 high tin aluminum alloy
C. 20 low tin aluminum alloy
D. 30 intermediate tin aluminum alloy
E. 15 medium tin aluminum alloy
F. 10 intermediate tin aluminum alloy
G. Low tin aluminum alloy
H. 20 high tin aluminum alloy
I. 30 high tin aluminum alloy
J. 50 high tin aluminum alloy
Answer: B
The grade of aluminum alloy piston material for marine medium and high-speed diesel engines is ().

Options:
A. ZL107
B. ZL108
C. ZL112
D. ZL109
E. ZL111
F. ZL106
G. ZL110
H. ZL105
I. ZL101
J. ZL104
Answer: B
The zinc content of brass in industrial production does not exceed 47%. When is the zinc content called two-phase brass?

Options:
A. 40%~46%
B. 25%~33%
C. 28%~34%
D. 36%~42%
E. 30%
F. 35%
G. 20%~30%
H. 47%~52%
I. 39%~45%
J. 39%
Answer: I
After cold processing, brass is prone to seasonal cracking in the atmosphere, seawater, or ammonia containing materials. What is the essence of this?

Options:
A. Internal etching
B. Structural embrittlement
C. Pitting corrosion
D. Atmospheric deterioration
E. Mechanical deformation
F. Oxidative wear
G. Selenium breakdown
H. Chemical corrosion
I. Electrochemical corrosion
J. Corrosion
Answer: I
What do 300 and 06 represent in KTH300-06?

Options:
A. Maximum yield strength and maximum elongation
B. Maximum tensile strength and maximum elongation
C. Minimum yield strength and minimum elongation
D. Minimum yield strength and minimum reduction in cross-sectional area
E. Maximum tensile strength and maximum reduction in cross-sectional area
F. Minimum tensile strength and minimum reduction in cross-sectional area
G. Maximum tensile strength and minimum elongation
H. Minimum tensile strength and minimum elongation
I. Minimum tensile strength and maximum elongation
J. Maximum yield strength and maximum reduction in cross-sectional area
Answer: H
What changes occur in gray cast iron after inoculation treatment to improve its mechanical properties?

Options:
A. Reduce graphite flake size
B. Miniaturization of graphite flakes
C. Changes in matrix structure
D. Elimination of graphite content
E. Make graphite flakes coarse
F. Larger graphite clusters
G. Grain refinement
H. Increase matrix porosity
I. Coarsening of grain structures
J. Addition of large impurities
Answer: B
The material mainly used for manufacturing diesel engine intake valves is ().

Options:
A. W18Cr4V
B. 15CrMo
C. 1Cr18Ni9Ti
D. 5Cr15Mo5
E. 2Cr13Ni8Ti
F. 3Cr10Si2
G. 20CrMo5
H. 4Cr9Si2
I. 7Cr4Vi
J. 12Cr8
Answer: H
Due to the high tempering stability, high stress, and residual austenite content of over 25% in the quenched structure, high-speed steel undergoes three rounds of tempering under ().

Options:
A. 600~800°C
B. 450~500°C
C. 700~750°C
D. 400~450°C
E. 650~700°C
F. 800~850°C
G. 300~350°C
H. 550~570°C
I. 500~600°C
J. 750~800°C
Answer: H
What is the conventional heat treatment for rolling bearing steel?

Options:
A. Normalizing+quenching+medium-temperature tempering
B. Carburizing+quenching+high-temperature tempering
C. Spheroidization annealing+quenching+medium-temperature tempering
D. Quenching+High temperature tempering
E. Quenching+Low temperature tempering
F. Spheroidization annealing+quenching+low-temperature tempering
G. Austenitizing+quenching+high-temperature tempering
H. Spheroidization annealing+quenching+high temperature tempering
I. Austenitizing+quenching+low-temperature tempering
J. Normalizing+quenching+low-temperature tempering
Answer: F
In a missile system, which of the following factors is most closely related to "range"?

Options:
A. The Weight and Shape of the Missile
B. Altitude and Maneuverability
C. Launch Platform and Software Algorithms
D. Guidance Systems and Sensor Accuracy
E. Fuel Type and Material Composition
F. Guidance Methods and Propulsion Methods
G. Payload and Control Systems
H. Wind Speed and Atmospheric Pressure
I. Launch Angle and Initial Velocity
J. Thrust Vector and Drag Coefficient
Answer: I
Which statement regarding the launch angle is correct?

Options:
A. The launch angle has little effect on the initial velocity.
B. The ideal launch angle is less than 30 degrees.
C. Angles above 60 degrees yield maximum range.
D. The launch angle has no effect on stability.
E. Stability improves with decreasing launch angles.
F. The maximum range is achieved at low angles.
G. The larger the launch angle, the farther the range.
H. Initial speed is independent of launch angle.
I. The launch angle affects only the trajectory shape.
J. The optimal launch angle is 45 degrees.
Answer: J
For steel gears with tooth hardness greater than 350 HBS, the process is generally ( ).

Options:
A. Processed Gear Blank - Gear Grinding - Gear Cutting - Quenching
B. Processing Gear Blanks -- Quenching -- Gear Grinding -- Polishing
C. Machining gear blanks -- Gear grinding -- Quenching -- Gear cutting
D. Gear Blanking -- Gear Cutting -- Quenching -- Gear Grinding
E. Machining gear blanks -- Quenching -- Gear Grinding -- Gear Cutting
F. Processing Gear Blanks--Cutting Teeth--Grinding Teeth--Quenching
G. Processing the gear blank -- Quenching -- Gear cutting -- Trimming
H. Gear processing--Tooth cutting--Tooth grinding--Quenching
I. Processing Gear Blanks -- Quenching -- Gear Cutting -- Gear Grinding
Answer: D
A reduction gear transmission, the main wheel 1 with 45 steel tempering, driven wheel 2 with 45 steel normalized, then the relationship between their teeth contact stress is ().

Options:
A. $$ \sigma_{\mathrm{H 1}}^\frac{1}{2}=\sigma_{\mathrm{H 2}}^\frac{1}{2} $$
B. $$ \sigma_{\mathrm{H 1}}<\sigma_{\mathrm{H 2}}^2 $$
C. $$ \sigma_{\mathrm{H 1}}^2=\sigma_{\mathrm{H 2}}^2 $$
D. $$
\sigma_{\mathrm{H 1}} > \sigma_{\mathrm{H 2}}
$$
E. $$
\sigma_{\mathrm{H 1}} < \sigma_{\mathrm{H 2}}
$$
F. $$
\sigma_{\mathrm{H 1}}=\sigma_{\mathrm{H 2}}
$$
G. $$
\sigma_{\mathrm{H 1}}>2\sigma_{\mathrm{H 2}}
$$
H. $$ \sigma_{\mathrm{H 1}} \leq \sigma_{\mathrm{H 2}} $$
I. $$ \sigma_{\mathrm{H 1}}\neq\sigma_{\mathrm{H 2}} $$
Answer: F
In the design of a straight-toothed cylindrical gear, if the center distance is kept constant and the module m is increased, it is possible to ().

Options:
A. Increase the contact strength of the tooth surface
B. The curvature and contact strength remain unchanged.
C. Both bending and contact strength can be enhanced
D. Reduce the bending strength of gear teeth
E. Increase the bending strength of the gear teeth
F. Increase the friction coefficient of the tooth surface.
G. Increase the friction coefficient of the gear teeth
H. Reduce the contact strength of the tooth surface
I. Reduce the fatigue life of the tooth surface
Answer: E
The tolerance zones of the inner and outer diameters of rolling bearings are () and are uniformly distributed with an upper deviation of () and a lower deviation of ().

Options:
A. Bidirectional control; true value; zero
B. Unidirectional control; Positive value; Zero
C. Bidirectional system; negative value; zero
D. Bidirectional control; zero; negative value
E. Unidirectional control; zero; positive value
F. Mixed system; negative value; positive value
G. Mixed system; zero; negative value
H. Mixed system; Zero; Positive value
I. Unidirectional control; Negative value; Zero
J. Unidirectional control; zero; negative value
Answer: J
When the rotational speed is high and both radial and axial loads are large, it is appropriate to use ( ).

Options:
A. Angular contact ball bearing
B. Spherical roller
C. Single-direction thrust ball bearing
D. Thrust roller bearing
E. Needle roller bearing
F. Linear sliding bearing
G. Self-aligning ball bearing
H. Deep groove ball bearing
I. Tapered Roller Bearing
J. Double row deep groove ball bearing
Answer: A
The tooth pitch (circumferential pitch) P() of the negative shift gear.

Options:
A. = 2πm
B. < πm
C. >πm
D. = πm
E. = πk
F. = πd
G. = m/π
H. = πb
I. > 2πm
Answer: D
What is the general method used to eliminate internal stresses in coil springs made from carbon spring steel wire by the cold coiling method?

Options:
A. Heat to the recrystallization temperature
B. Cooling Rate Control
C. Low Temperature Tempering Treatment
D. High Temperature Annealing Treatment
E. Heat treatment followed by extrusion
F. Squeeze and then heat treat
G. Normalizing Treatment
H. Medium Temperature Tempering Treatment
I. Quenching Treatment
J. High temperature tempering treatment
Answer: C
If the image function
$$
F ( s ) \!=\! {\frac{s^{2} \!+\! s \!+\! 1} {( s^{2} \!+\! 4 ) \, ( s \!+\! 2 )}}
$$
of the Laplace transform, the domain of convergence is σ > 0 then the corresponding original function ft) =____.

Options:
A. $$
f ( t )={\frac{1} {8}} \left[ \mathrm{c o s} 7 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
B. $$
f ( t )={\frac{1} {8}} \left[ 5 \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
C. $$
f ( t )={\frac{1} {2}} \left[ \mathrm{c o s} 7 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
D. $$
f ( t )={\frac{1} {8}} \left[ \mathrm{c o s} 5 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
E. $$
f ( t )={\frac{1} {2}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
F. $$
f ( t )={\frac{1} {5}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
G. $$
f ( t )={\frac{1} {8}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
H. $$
f ( t )={\frac{3} {8}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
I. $$
f ( t )={\frac{1} {3}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{-2 t} \right] e \left( t \right)
$$
J. $$
f ( t )={\frac{1} {8}} \left[ \mathrm{c o s} 2 t-\mathrm{s i n} 2 t+3 \mathrm{e}^{1-2 t} \right] e \left( t \right)
$$
Answer: B
When conducting microbiological tests on food, which part of shrimp is usually tested?

Options:
A. Head and tail segments
B. Muscles within the abdominal segments
C. Tail muscle
D. Antennae and eyes
E. Digestive and circulatory system
F. Gills and appendages
G. External shell surfaces
H. Whole shrimp
I. Head muscles
J. Legs and pincers
Answer: B
What is the standard electrode potential?

Options:
A. The potential of an electrode when paired with a non-standard hydrogen electrode.
B. The potential difference between a standard electrode and a non-standard electrode.
C. The electromotive force generated by a battery using only a standard hydrogen electrode.
D. The potential of a certain electrode in its standard state
E. The electromotive force of a cell consisting of a certain electrode and a standard hydrogen electrode
F. The voltage across a certain electrode when exposed to standard environmental conditions.
G. The electromotive force across a cell using a standard electrode and a typical metal electrode.
H. The potential of a certain electrode at 25°C
I. The electromotive force of the battery formed by a certain electrode in a non-standard state and a standard hydrogen electrode.
J. The electromotive force of the battery composed of a certain electrode in its standard state and the standard hydrogen electrode.
Answer: J
What is the purpose of using alloy steel for spring materials?

Options:
A. To enhance thermal stability under stress.
B. To amplify magnetic properties for motors.
C. To increase sound absorption properties.
D. To boost chemical resistance against corrosion.
E. To improve aesthetic appeal with color finish.
F. To reduce overall weight and save costs.
G. To increase electrical conductivity for wiring.
H. To decrease expansion and contraction rates.
I. To enhance flexibility for better performance.
J. To ensure good hardenability during heat treatment.
Answer: J
To increase the contact strength of gear transmission, what method can be adopted?

Options:
A. Increase the weight of the gear transmission.
B. Increase the center distance of transmission.
C. Decrease the center distance of transmission.
D. Decrease the operating temperatures.
E. Decrease the material density of gears.
F. Increase the speed rate of transmission.
G. Decrease the width of gear teeth.
H. Decrease the overall size of the gear.
I. Increase the alignment precision of axes.
J. Increase the gear surface lubrication.
Answer: B
When the poles of the system fall on the negative real axis of the complex plane s, which of the following statements about the damping ratio of the system is correct?

Options:
A. The damping ratio is between 0 and 1.
B. The damping ratio fluctuates around 1.
C. The damping ratio is greater than 2.
D. The damping ratio is exactly equal to 1.
E. The damping ratio is less than or equal to 1.
F. The damping ratio is less than 1.
G. The damping ratio equals 2.
H. The damping ratio is greater than or equal to 1.
I. The damping ratio equals 0.
J. The damping ratio is strictly less than 0.
Answer: H
Which of the following statements about the open-loop frequency response curve of a Type Zero system on the complex plane is correct?

Options:
A. It starts at a point on the imaginary axis and ends at another point on the real axis.
B. It emerges from a point in the upper half-plane and ends in the lower half-plane.
C. It starts at a point on the real axis and ends at another point on the real axis.
D. It originates from a point on the negative imaginary axis and finishes on the positive imaginary axis.
E. It initiates from a location in the right half-plane and finishes in the left half-plane.
F. It commences at a point on the imaginary axis and concludes on the imaginary axis.
G. It begins at a point on the imaginary axis and terminates on the real axis.
H. It begins at a point in the lower half-plane and terminates on the upper half-plane.
I. It departs from a point on the negative real axis and completes on the positive real axis.
J. It originates from a point in the left half-plane and concludes in the right half-plane.
Answer: C
The downward-discharge external grooved wheel seeder sows large seeds by changing the _____.

Options:
A. Speed of the sowing wheel
B. Position of the seed-rowing tongue
C. Rotation of the seeder handle
D. Pressure applied to seeds
E. Weight of the seeds in the hopper
F. Direction of the wind movement
G. Presence of moisture in the soil
H. Construction material of the groove wheel
I. Type of seed being sown
J. Height of the sowing wheel base
Answer: B
Circular hole sieves are used to separate ____.

Options:
A. Light of different brightness
B. Air of varying humidity
C. Soil of different moistures
D. Sand of varying coarseness
E. Grain of different widths
F. Metals of different magnetism
G. Rocks of differing hardness
H. Oil of different viscosities
I. Gas of different densities
J. Water of varying temperatures
Answer: E
Liquid pumps in plant protection machinery are used to press the liquid to overcome the resistance of the pipeline, improve the atomization capacity, and increase the _____.

Options:
A. Range and spray pattern
B. Heat dissipation and sound reduction
C. Height and pump efficiency
D. Speed and rotational force
E. Strength and color intensity
F. Pressure and temperature shocks
G. Weight and fluid density
H. Leak resistance and spill control
I. Volume and viscosity alterations
J. Flow and fluid thickness
Answer: A
Reciprocating cutter mainly consists of power blade, fixed blade, cutter bar, edge guard, ____, etc.

Options:
A. cooling fan
B. grip handle
C. engine turbine
D. presser blade
E. safety latch
F. adjustment knob
G. power switch
H. lever arm
I. cutting wire
J. height regulator
Answer: D
Teak solid wood has a volume of 10 x 10 x 3 cm, its absolute dry density is 0.5, what is its porosity?

Options:
A. 66.7%
B. 50.0%
C. 77.8%
D. 72.2%
E. 33.3%
F. 44.4%
G. 55.5%
H. 88.9%
I. 80.0%
J. 20.0%
Answer: A
What is on the side near the bark direction within an annual ring?

Options:
A. Earlywood
B. Middlewood
C. Sapwood
D. Outerwood
E. Barkwood
F. Earlybark
G. Heartwood
H. Innerwood
I. Latewood
J. Centerwood
Answer: I
The PH value of wood refers to the degree of acidity and alkalinity of water-soluble substances in wood, and what is the PH value of most woods?

Options:
A. 5.0-7.0
B. 8.5-10.5
C. 7.5-9.5
D. 9.0-11.0
E. 3.0-5.0
F. 4.0-6.0
G. 7.0-9.0
H. 6.5-8.5
I. 10.0-12.0
J. 2.0-4.0
Answer: F
What is the minimum density of a piece of wood?

Options:
A. Basic density
B. Surface density
C. Initial density
D. Air-dry density
E. Critical density
F. Normal density
G. Absolute density
H. Common density
I. Substantial density
J. Minimum density
Answer: A
Among the following options, which description related to "pinocytosis" is correct?

Options:
A. The phenomenon where living cells release liquid substances without relying on permeability from the external environment.
B. The phenomenon whereby living cells absorb liquid substances from the environment without relying on permeability.
C. The phenomenon where dead cells rely on permeability to absorb liquid substances from the outside environment.
D. The phenomenon where dead cells do not absorb liquid substances from the outside environment due to lack of permeability.
E. The phenomenon where living cells expel solid substances from the outside without relying on permeability.
F. The phenomenon in which dead cells do not absorb liquid substances from the outside world due to permeability.
G. The phenomenon where living cells rely on permeability to absorb solid substances from the external environment.
H. Apoptotic cells release liquid substances externally through membrane blebbing.
I. The phenomenon whereby living cells rely on permeability to absorb liquid substances from the outside environment.
J. The phenomenon where living cells absorb solid substances from the outside environment without relying on permeability.
Answer: B
Among the following options, which one correctly describes the "air permeability coefficient"?

Options:
A. When the wind direction is parallel to the shelterbelt, the ratio of the average wind speed below the height of the shelterbelt on the leeward edge of the shelterbelt to the average wind speed at the same height in an open field.
B. When the wind direction is perpendicular to the forest belt, the ratio of the average wind speed above the height of the windward edge of the forest belt to the average wind speed below the same height in the open field.
C. When the wind direction is perpendicular to the forest belt, the ratio of the average wind speed at the windward edge of the forest below the height of the forest belt to the average wind speed in the open field at the same height below.
D. When the wind direction is perpendicular to the forest belt, the ratio of the average wind speed above the height of the forest belt on the leeward side to the average wind speed at the same height below in the open field.
E. When the wind direction is parallel to the forest belt, the ratio of the maximum wind speed below the height of the forest belt on the leeward edge of the forest belt to the maximum wind speed at the same height in the open field.
F. When the wind direction is perpendicular to the forest belt, the ratio of the average wind speed below the height of the forest edge on the lee side of the forest belt to the average wind speed at the same height below in the open field.
G. When the wind direction is parallel to the forest belt, the ratio of the average wind speed above the height of the forest belt on the windward edge of the forest to the average wind speed below the same height in the open field.
H. When the wind direction is parallel to the forest belt, the ratio of the average wind speed above the height of the forest belt on the leeward side of the forest edge to the average wind speed at the same height below in the open field.
I. When the wind direction is parallel to the forest belt, the ratio of the average wind speed at the windward edge of the forest below the height of the forest belt to the average wind speed below the same height in the open field.
J. When the wind direction is perpendicular to the forest belt, the highest wind speed on the leeward edge of the forest belt, below the height of the forest belt, compared to the highest wind speed in the open field at the same height below.
Answer: F
As human industrial activities have expanded, global ecological and environmental issues have become increasingly severe. Among the options below, which description of "ecological and environmental issues" is correct?

Options:
A. The problem of deforestation and its impact on biodiversity and soil quality caused by industrial growth due to urban construction and various demands in the process of human survival and development.
B. Indicates that due to natural disasters, the direct or indirect impact leads to the exhaustion of resources necessary for human survival and environmental degradation.
C. Highlighting the emissions of chemical substances in industrial activities and their long-term pollution issues on water bodies, air, and soil.
D. This refers to various negative feedback effects that endanger human survival and development in the process of utilizing and transforming nature by humans.
E. This refers to the damage to the natural ecology and the impact on climate change caused by the increased construction land during the process of urbanization.
F. Indicates issues of uneven resource distribution and negative environmental changes arising from the accelerating pace of technological development.
G. This refers to the harmful effects on human health caused by the damage and pollution of the natural environment, which occurs during the process of utilizing and transforming nature for human survival and development.
H. This refers to the loss of biodiversity in natural ecosystems and its long-term negative impacts on global climate change.
I. This refers to the issues of global water shortages and the decline of ecosystem functions caused by climate change.
J. This refers to the effects on economic development caused by the damage and pollution to the natural environment, which occur during the process of humans using and transforming nature for their own survival and development.
Answer: D