TASK DEFINITION: You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.
PROBLEM: Background Paragraph: Predators play an important role in an ecosystem. For example, if they did not exist, then a single species could become dominant over others. Grazers on a grassland keep grass from growing out of control. Predators can be keystone species . These are species that can have a large effect on the balance of organisms in an ecosystem. For example, if all of the wolves are removed from a population, then the population of deer or rabbits may increase. If there are too many deer, then they may decrease the amount of plants or grasses in the ecosystem. Decreased levels of producers may then have a detrimental effect on the whole ecosystem. In this example, the wolves would be a keystone species. 
Story: Two students studied animal behavior for the biology class. Ned studied more about predators, while Kim studied more about herbivores. 
Question: Which student studied less about keeping grass from growing out of control?

SOLUTION: Ned.

PROBLEM: Background Paragraph: There was no additional air in the tire the second time Lawrence checked the air pressure, but something did change between the two measurements. The tires had rolled over 10 miles of road on the trip to school. Any time one surface moves over another, it causes friction. Friction is a force that opposes the motion of two surfaces that are touching, and friction between two surfaces always generates heat. Quickly rub your hands together and you’ll feel the heat generated by the friction between them. As the tires moved over the road, friction between the tires and road generated heat. In short, the tires got warmer and so did the air inside them. 
Story: There was a carnival game at the fair that allowed you to win a basketball if you could correctly guess which of the two balls had spun around a circular track more times. Each ball would be dropped into identical circular tracks and then a curtain would cover them. Ball A would then spin around the track a certain amount of times, and Ball B would spin around a certain amount of times. After they were done spinning, you had to guess which ball completed more revolutions. A boy came up and had no idea how to figure out the answer, but when he picked them up he noticed that Ball A was slightly warmer than Ball B. 
Question: Which ball completed more revolutions?

SOLUTION: Ball A.

PROBLEM: Background Paragraph: Located mostly in the Arctic north polar region in the middle of the Northern Hemisphere, the Arctic Ocean is almost completely surrounded by Eurasia and North America. It is partly covered by sea ice throughout the year and almost completely in winter. The Arctic Ocean's surface temperature and salinity vary seasonally as the ice cover melts and freezes; its salinity is the lowest on average of the five major oceans, due to low evaporation, heavy fresh water inflow from rivers and streams, and limited connection and outflow to surrounding oceanic waters with higher salinities. The summer shrinking of the ice has been quoted at 50%. The US National Snow and Ice Data Center (NSIDC) uses satellite data to provide a daily record of Arctic sea ice cover and the rate of melting compared to an average period and specific past years. 
Story: John sailed across two oceans last year. First, he sailed across the Atlantic Ocean, which he noted as location A. Then he sailed across the Arctic Ocean, which he noted as location B. He was so amazed by the Arctic Ocean that he sailed across that ocean twice, time C and time D. Time C was in the summer,and time D was in the winter. 
Question: Which would have more ice cover, time C or time D?

SOLUTION:
time D.