### handle | knob:

Doorknob
* Some doorknobs are part of abbeys
  - architecture
  - barns
  - buildings
  - castles
  - cathedrals
  - churches
  - convents
  - coops
  - greenhouses
  - hospitals
  - hotels
  - inns
  - kennels
  - manors
  - monasteries
  - mosques
  - observatories
  - palaces
  - restaurants
  - rinks
  - skyscrapers
  - temples
  - theaters
* are a small, cheap portable item that quickly make a place look more expensive than it is
  - construction materials
  - eye-level
* are located in front doors
  - rooms
  - man-made
  - mechanical devices
  - part of doors

### handling:

Washing dish
* are handling
  - houseworks
  - washings
* is women's work.

### handmade:

Peruvian bead
* are handmade.
* seem to come in many shapes and sizes.

### hands-on sciences:

Plant science
* are hands-on sciences.
* has a long history.
* is the fundamental life science.

### haplodiploid:

Sweat bee
* Most sweat bees collect pollen.
* are haplodiploid
  - metallic green
  - very small
* get their name from an attraction to people who are perspiring.

Happening
* are events.
* is an event
  - bands

Hard copy
* Hard copies are matter.
* is matter

Hard object
* are things like buildings, hills, and mountains.
+ Electronics, Pulse circuits
  * Hard objects are things like buildings, hills, and mountains. Metallic objects are anything made of metal, like aircraft, bridges, or even objects in space, like satellites. The reflected radar energy is detected by radar pulse receivers which use both pulse and digital circuits together. The pulse and digital circuits in radar pulse receivers are used to show the location and distance of objects which have reflected the radar transmitter's high powered pulses.

Hardness
* Some hardness is needed in plumbing systems to prevent corrosion of pipes.
* affects absorption levels.
* increases somewhat with higher atomic number.
* is quality

### hardness:

Carbonate hardness
* becomes apparent after water has been heated.
* plays an important role in the buffering capacity of water.

Permanent hardness
* involves sulphates and is unaffected by heat.
* is determined by the amount of calcium and magnesium ions present in the water.

Shore hardness
* is measured using a device called a durometer.
* strong indicator of modulus.

### hardness:

Water hardness
* affects delivery systems more than the bird.
* can reduce glyphosate effectiveness as can the use of high water volumes.
* describes the total amount of calcium present in the water.
* has a major effect on pH and pH stability
  - no effect on animal health
* is an indication of calcium and magnesium in the water
  - indicator of salt concentration
* is caused by calcium and magnesium salts
  - dissolved minerals, usually calcium and magnesium
  - classified based on concentration of calcium carbonate the water contains
  - determined mainly by the amount of dissolved magnesium and calcium ions there are
  - expressed in degrees of hardness
  - linked to scale formation and the reduced cleaning efficiency of soaps
* is measured in grains per gallon
  - the units called grains
  - reported as milligrams per liter, parts per million or grains per gallon
* problem in many areas.
* rating of how much salt is present in the water.
* varies throughout the United States
  - with geographic locations

Harmful chemical
* Some harmful chemicals kill animals
  - other animals
* appear regularly in our tap water.
* are in stormwater running off roads, parking lots, houses, and lawns.
* can be in new carpets and in furniture made of particle board.
* leach out and poison wildlife.

Harmful organism
* can get onto the seeds after they leave the field, too
  - live in the soil
* thrive in the warmth and moisture present in restrooms and shower rooms.

### harmful:

Psychiatric treatment
* are harmful
  - medical treatments
* is as effective in the elderly as in younger age groups.