Q: Background: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe's neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks. Paragraph: Mike lives in a cold mid-western city, where there is not much predator prey interaction. Mike noticed that in his city some squirrels have darker coat, while others have lighter coat. He also knew that darker coats are more suitable in cold environment with less predator prey interaction. He started thinking why the squirrels developed different coat colors. Given the paragraph above, please answer correctly the following question: Which squirrels would have smaller chance of survival, lighter or darker?
A: lighter

Q: Background: As the thermal expansion is the key factor to the sea level variability, decreased heat content should result in a reduction in global mean sea levelon a decadal time scale.[2] However, Grinsted [2007] argued that a significant sea level rise is the first direct response to the volcanic eruption, and after that sea level becomes to drop. One possible explanation for this phenomenon is the imbalance of ocean mass fluxes. After the volcano eruption, evaporation over ocean becomes lower, because it is largely determined by the ocean skin temperature change. The quick response of evaporation to the surface cooling and the delayed response of river runoff to the associated lower precipitation lead to an increased sea level. About 1~2 years later, river discharge becomes less due to the reduced precipitation and less sea ice melting, which cause sea level to drop.[9] Paragraph: In the beginning of year 1000 mount Etna had a huge volcanic eruption. To test the effect of volcanic eruption on sea level scientists measured geological data through carbon dating. They measured the data for four different time point - for year 998, year 1000, year 1002, and year 1010. Scientists now need to compare and analyze these data. Given the paragraph above, please answer correctly the following question: Without considering Grinsted's theory, which year would have higher sea level, year 998 or year 1010?
A: year 998

Q: Background: Water stratification is when water masses with different properties - salinity (halocline), oxygenation (chemocline), density (pycnocline), temperature (thermocline) - form layers that act as barriers to water mixing which could lead to anoxia or euxinia.[1] These layers are normally arranged according to density, with the least dense water masses sitting above the more dense layers. Water stratification also creates barriers to nutrient mixing between layers. This can affect the primary production in an area by limiting photosynthetic processes. When nutrients from the benthos cannot travel up into the photic zone, phytoplankton may be limited by nutrient availability. Lower primary production also leads to lower net productivity in waters.[2] Paragraph: Scientists studied water stratification in two saltwater lakes. they were trying to find out why the fish population decreased in Long lake, and was very healthy and abundant in Shoal lake. They found out the phenomenon occurred more often in Long lake, leading to very many unpleasant chain effects. Given the paragraph above, please answer correctly the following question: Which lake had less denser layers of water?
A: Shoal lake

Q: Background: A large log placed in a fire will burn relatively slowly. If the same mass of wood were added to the fire in the form of small twigs, they would burn much more quickly. This is because the twigs provide a greater surface area than the log does. An increase in the surface area of a reactant increases the rate of a reaction. Surface area is larger when a given amount of a solid is present as smaller particles. A powdered reactant has a greater surface area than the same reactant as a solid chunk. In order to increase the surface area of a substance, it may be ground into smaller particles or dissolved into a liquid. In solution, the dissolved particles are separated from each other and will react more quickly with other reactants. Paragraph: Two groups of teens studied fire for the physics class. Group S made a fire using large logs, while group F made a fire using small twigs and sawdust. Both groups used the same volume of wood. Given the paragraph above, please answer correctly the following question: Which group made a fire from fewer particles of wood?
A:
Group S