instruction:
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.
question:
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 14 last week. On Friday, there were 1511 motorcyclists. On Saturday, there were 2511 motorcyclists. On Sunday, there were 3511 motorcyclists. On Monday, there were 4511 motorcyclists. On Tuesday, there were 5511 motorcyclists. On Wednesday, there were 6511 motorcyclists. On Thursday, there were 7511 motorcyclists. 
Question: What day had a lower crash rate per cyclist: Friday or Thursday?
answer:
Thursday.


question:
Background Paragraph: The Human Immunodeficiency Virus ( HIV ) is the virus that causes Acquired Immunodeficiency Syndrome ( AIDS ). Most researchers believe that the HIV originated in sub-Saharan Africa during the 20th century. HIV is transmitted by sexual contact and by contact with infected bodily fluids, such as blood, semen, breast milk, and vaginal secretions. It is also passed from mother to fetus. HIV is now a pandemic , with an estimated (as of 2008) 38.6 million people now living with the disease worldwide. It is estimated that AIDS has killed more than 25 million people since it was first recognized in 1981. 
Story: Dean and Paul both went to volunteered in Africa. They had a blood test when they came back. Paul had been infected with the HIV virus while Dean was healthy and clean. 
Question: Which friend has a virus that is transmitted by contact with infected semen?
answer:
Paul.


question:
Background Paragraph: Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.  Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid. 
Story: China used alternative fuels to generate electricity, while Mongolia burned lots of fossil fuels. There were frequent debates between the two countries on this matter. 
Question: Which country caused more deforestation?
answer:

Mongolia.