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: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. 
Story: Two countries used different methods to produce their energy. Albania used fossil fuels, while Croatia used Nuclear fission. 
Question: Which country used fewer radioactive elements?

SOLUTION: Albania.

PROBLEM: Background Paragraph: For most substances, when the temperature of the solid is raised high enough, the substance changes to a liquid, and when the temperature of the liquid is raised high enough, the substance changes to a gas. We typically visualize a solid as tiny particles in constant motion held together by attractive forces. As we add heat to the solid, the motion, or the kinetic energy, of the particles increases. At some temperature, the motion of the particles becomes great enough to overcome the attractive forces. The thermal energy that was added to the solid up to this point was absorbed by the solid as kinetic energy, increasing the speed of the molecules. The lowest temperature at which the particles are able to exist in the liquid form is called the melting point . 
Story: As a science experiment for his school homework, Kendra is putting two ice cubes on separate pans and then putting those pans on burners set to different temperatures. Ice cube A is set on top of a burner set to a low temperature, and ice cube B is placed on a burner set quite a bite higher. One minute later, Kendra begins writing down what she sees happening to the ice cubes. 
Question: Is ice cube A or ice cube B farther from its melting point?

SOLUTION: Ice cube A.

PROBLEM: Background Paragraph: There is an evolution in tennis training that employs the use of low compression balls and in some cases modified court sizes. Organizations around the world have begun to use lower compression balls and modified court sizes as a way to reach out to younger tennis players interested in tennis. The use of low compression balls and modified court sizes is meant to ease the process into becoming a competitive or amateur tennis player. The low compression balls are colored differently to indicate the level of compression. Young players and beginners are likely to find the game easier to learn because the balls do not bounce as high or travel as fast as "normal" balls. The modified smaller courts make covering the court, or reaching the opponents shot, easier as well. 
Story: Jordan and his brother William are going to a special school for learning tennis. When they arrive the instructor asks each of them what level they believe they are as players. William has attended tournaments in the past so he believes himself to be competitive. Jordan on the other hand is just learning so he says he is an amateur. The instructor then hands each of them a tube of tennis balls. William gets a tube of normal tennis balls. Jordan gets a tube of tennis balls that are colored slightly different and labeled "low compression". They practice side by side and Jordan notices that when he hits his tennis balls they do not bounce as high or as fast as Williams normal tennis balls. He ask William if he can try one of his and the balls bounce much higher and faster. 
Question: Will a competative tennis player use a normal tennis ball or a low compression tennis ball.?

SOLUTION:
a normal tennis ball.