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.
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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: Sam and Ned went on vacation, The 2 friends partied nights and spent their days on the beach. Sam started getting flu like symptoms, so he went to the doctor's office where he found out that he was infected with HIV. Ned got scared when he heard what happened, but fortunately he was OK.
Question: Which friend had a virus that causes Acquired Immunodeficiency Syndrome?

Answer: Sam.

Question: Background Paragraph: The stronger of two acids will have a higher Ka than the weaker acid; the ratio of hydrogen ions to acid will be higher for the stronger acid as the stronger acid has a greater tendency to lose its proton. Because the range of possible values for Ka spans many orders of magnitude, a more manageable constant, pKa is more frequently used, where pKa = log10 Ka. Stronger acids have a smaller pKa than weaker acids. Experimentally determined pKa at 25 C in aqueous solution are often quoted in textbooks and reference material.
Story: Jacob and Thomas were conducting an experiment in a chemistry class. The goal of the experiment was to identify the strength of unknown acids by examining the products formed in a chemical reaction. After they completed the experiment, Jacob concluded that he was given a strong acid, while Thomas concluded that he was given a weak acid.
Question: Which person's acid, Jacob's or Thomas's, will have a larger pKa?

Answer: Thomas's.

Question: Background Paragraph: In addition to insects, weeds have also been a menace to farmers - just ask anyone with a garden how much they hate weeds. They can quickly compete for water and nutrients needed by other plants. Sure, farmers can use herbicides to kill weeds, but do these chemicals also harm the crops? Can biotechnology help with this issue? Some crops have also been genetically engineered to acquire tolerance to the herbicides - allowing the crops to grow, but killing the weeds. But the lack of cost effective herbicides with a broad range of activity - that do not harm crops - is a problem in weed management. Multiple applications of numerous herbicides are routinely needed to control the wide range of weeds that are harmful to crops. And at times these herbicides are being used as a preventive measure that is, spraying to prevent weeds from developing rather than spraying after weeds form. So these chemicals are being added to crops. This practice is followed by mechanical and/or hand weeding to control weeds that are not controlled by the chemicals. Crops that are tolerant of herbicides would obviously be a tremendous benefit to farmers ( Figure above ). The introduction of herbicide tolerant crops has the potential to reduce the number of chemicals needed during a growing season, thereby increasing crop yield due to improved weed management and decreased harm to the crops.
Story: Because of the weed and insect menace villagers from North village decided to use herbicide tolerant crops. South village decided to postpone a decision and kept using regular seeds.
Question: Which village didn't reduce the number of chemicals needed during a growing season?

Answer:
South.