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.

Q: Background Paragraph: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs. 
Story: John has been hearing about climate change for last couple of years. He wants to understand the science behind climate change. For that, he picked up two eras in earth's history, era A and era B. Era A was hundred thousand years ago, and era B is in the present day. He now wants to compare these to eras to understand the change in climate better. 
Question: Which era would have seen less fossil fuel burning, era A or era B?

A: era A.
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Q: Background Paragraph: Turner et al (2006) derived crash prediction models for this report’s predecessor and found a
pronounced ‘safety in numbers’ effect in the models. Using the crash prediction model for mid-block
locations, generic motorist and cyclist volumes can be used to demonstrate the impacts on the
expected crash rate of varying motor vehicle and cycle volumes. As shown in figure 2.20, an increase
in the proportion of cyclists to the overall traffic volume causes an increase in expected crashes at
mid-block locations, but the crash rate increases at a decreasing rate. That is to say, the crash rate per
cyclist goes down as the cycle volume increases. 
Story: There were a lot of motorcycles on Interstate 10 last week. On Tuesday, there were 3500 motorcyclists. On Wednesday, there were 4500 motorcyclists. On Thursday, there were 5500 motorcyclists. On Friday, there were 6500 motorcyclists. On Saturday, there were 7500 motorcyclists. On Sunday, there were 8500 motorcyclists. On Monday, there were 9500 motorcyclists. 
Question: What day had a lower crash rate per cyclist: Thursday or Monday?

A: Monday.
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Q: Background Paragraph: One result of air pollution is acid rain. Acid rain is precipitation with a low (acidic) pH. This rain can be very destructive to wildlife. When acid rain falls in forests, freshwater habitats, or soils, it can kill insects and aquatic life. It causes this damage because of its very low pH. Sulfur oxides and nitrogen oxides in the air both cause acid rain to form ( Figure below ). Sulfur oxides are chemicals that are released from coal-fired power plants. Nitrogen oxides are released from motor vehicle exhaust. 
Story: Two countries were neighbors, separated by a mountain range. Ghana used fossil fuels to produce energy, but one of the consequences of that was increased air pollution and acid rain. Brunei was a country inhabited by nature lovers and tree huggers, so they were very protective of their environment. 
Question: Which country had smaller amounts of low pH precipitation in the forests?

A:
Brunei.
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