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.

Example Input: Background Paragraph: Shown in the Figure below is a cylinder of gas on the left that is at room temperature (300 K). On the right, the cylinder has been heated until the Kelvin temperature has doubled to 600 K. The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles. Decreasing the temperature would have the opposite effect, and the pressure of an enclosed gas would decrease.
Story: Nicholas works in pest control, and needs to have a steady supply of nitrogen gas for his tools. He always keeps a
closed container of nitrogen gas in his freezer, where the temperature is very low. Nicholas's neighbor, Justin, likes to grill in his backyard. Justin, therefore, always keeps a closed container of propane gas outside, where the temperature is high.
Question: Molecules of which gas will collide against the walls of their respective container with more force?
Example Output: propane gas.

Example Input: Background Paragraph: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution that harms the health of living things. The air pollution also causes acid rain and contributes to global warming. In addition, fossil fuels are nonrenewable resources, so if we keep using them, they will eventually run out. The main advantage of nuclear energy is that it doesn't release air pollution or cause the other environmental problems associated with the burning of fossil fuels. On the other other hand, radioactive elements are nonrenewable like fossil fuels and could eventually be used up.
Story: Canada produced its electricity by using fossil fuels and nuclear fission. New Zealand used only alternative, renewable sources to produce their electricity.
Question: Which country used more non-renewable resources?
Example Output: Canada.

Example Input: Background Paragraph: Rainfall in an area is important because it influences the rate of weathering. More rain means that more rainwater passes through the soil. The rainwater reacts chemically with the particles. The top layers of soil are in contact with the freshest water, so reactions are greatest there. High rainfall increases the amount of rock that experiences chemical reactions. High rainfall may also carry material away. This means that new surfaces are exposed. This increases the rate of weathering.
Story: Rob is an environmental scientist. He is looking at two samples of soil, sample A and sample B. Sample A is from Amazon Rain-forest, where they get one of the highest rainfall in the world. Sample B is from the Atacama Desert, where they get one of the lowest rainfall in the world. He needs to determine the properties of these samples.
Question: Would new surfaces be exposed or stay covered in sample A?
Example Output:
exposed.