Background: As new seafloor forms and spreads apart from the mid-ocean ridge it slowly cools over time. Older seafloor is, therefore, colder than new seafloor, and older oceanic basins deeper than new oceanic basins due to isostasy. If the diameter of the earth remains relatively constant despite the production of new crust, a mechanism must exist by which crust is also destroyed. The destruction of oceanic crust occurs at subduction zones where oceanic crust is forced under either continental crust or oceanic crust. Today, the Atlantic basin is actively spreading at the Mid-Atlantic Ridge. Only a small portion of the oceanic crust produced in the Atlantic is subducted. However, the plates making up the Pacific Ocean are experiencing subduction along many of their boundaries which causes the volcanic activity in what has been termed the Ring of Fire of the Pacific Ocean. The Pacific is also home to one of the world's most active spreading centers (the East Pacific Rise) with spreading rates of up to 13 cm/yr. The Mid-Atlantic Ridge is a "textbook" slow-spreading center, while the East Pacific Rise is used as an example of fast spreading. Spreading centers at slow and intermediate rates exhibit a rift valley while at fast rates an axial high is found within the crustal accretion zone. The differences in spreading rates affect not only the geometries of the ridges but also the geochemistry of the basalts that are produced.Since the new oceanic basins are shallower than the old oceanic basins, the total capacity of the world's ocean basins decreases during times of active sea floor spreading. During the opening of the Atlantic Ocean, sea level was so high that a Western Interior Seaway formed across North America from the Gulf of Mexico to the Arctic Ocean. Paragraph: A scuba diver is currently exploring the ocean floor. During the day she happens upon two different ocean basins. For some reason, both have signs next to each basin indicating how old they are. According to the signs, basin D is significantly older than basin F. The scuba diver decides to explore basin F first and then will look around in basin D on her return trip. Given the paragraph above, please answer correctly the following question: Which basin has a cooler floor?
Ans: basin D

Background: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. Its rate of loss has slowed with restrictions on pollutants, but it is still at risk. Paragraph: Two neighboring habitable planets from the same solar system, planet U and planet N, had Earth-like atmospheres. The inhabitants of planet U destroyed the ozone layer by their actions, while their neighboring planet N didn't. Given the paragraph above, please answer correctly the following question: Which planet had inhabitants that used fewer aerosol coolants?
Ans: planet N

Background: Start right above point on the temperature axis and follow the red line vertically. At very low pressure, the particles of the substance are far apart from one another and the substance is in the gas state. As the pressure is increased, the particles of the substance are forced closer and closer together. Eventually the particles are pushed so close together that attractive forces cause the substance to condense into the liquid state. Continually increasing the pressure on the liquid will eventually cause the substance to solidify. For the majority of substances, the solid state is denser than the liquid state and so putting a liquid under great pressure will cause it to turn into a solid. The line segment represents the process of sublimation, where the substance changes directly from a solid to a gas. At a sufficiently low pressure, the liquid phase does not exist. The point labeled is called the triple point . The triple point is the one condition of temperature and pressure where the solid, liquid, and vapor states of a substance can all coexist at equilibrium. Paragraph: John is learning about different states of matter. So far, he recognized three states of matter, state A, state B, and state C. State A is in solid state. State B is in liquid state, and state C is in gaseous state. He needs to learn more about their individual characteristics. Given the paragraph above, please answer correctly the following question: Which state would most likely be denser, state A or state B?
Ans: state A

Background: Human beings invented agriculture about 10,000 years ago. This provided a bigger, more dependable food supply. It also allowed people to settle down in villages and cities for the first time. Birth rates went up because there was more food and settled life had other advantages. Death rates also rose because of crowded living conditions and diseases that spread from domestic animals. Because the higher birth rates were matched by higher death rates, the human population continued to grow very slowly. Paragraph: Gary researched two old human settlements. Village A was smaller, it existed about 12,000 years ago. He also studied village B, which existed about 6,000 years ago. The village was much bigger and better developed. Given the paragraph above, please answer correctly the following question: Which village existed before the invention of agriculture?
Ans: Village A