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.

Ex Input:
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: Hydrologists studied two samples of rain water. Jim studied an acid rain sample from a nearby city, and Dan studied a sample of water from another town. 
Question: Which hydrologist learned that acid rain falls in freshwater habitats?

Ex Output:
Jim.


Ex Input:
Background Paragraph: Alcoholic beverages do not make the entire body warmer.[361] The reason that alcoholic drinks create the sensation of warmth is that they cause blood vessels to dilate and stimulate nerve endings near the surface of the skin with an influx of warm blood. This can actually result in making the core body temperature lower, as it allows for easier heat exchange with a cold external environment. 
Story: Two people got stuck in a local  blizzard. Tom had a bottle of alcohol with him and drank it after he found some kind of shelter in the snow. Dan didn't have alcohol with him. 
Question: Which of the two people had a larger influx of warm blood near the surface of the skin?

Ex Output:
Tom.


Ex Input:
Background Paragraph: Besides anthropogenic productivity of the land, the biodiversity of degraded land also declines, as previously mentioned.[12] With less biodiversity, this ecosystem is less adaptable to when disasters strike it[11][8] It has a smaller available food supply, in terms of plants, for animals, who then may die out or more likely may relocate. Proof of this decline is that presently 15-20% of Tibetan Plateau species are now considered endangered; and now because of this animal and plant absence, the soil quality of these degraded lands is very poor.[1] It does not hold the necessary nutrients, such as water, nitrogen, and carbon, essential to either supporting life or inviting life back to that land.[6] As a result of such carbon and nitrogen loss in the Tibetan Plateau, $8,033/ha and $13,315/ha were respectively lost in economic terms. Soils are further weakened by dust storms whose frequency increases because of degradation.[11][4] Erosion of soil becomes a bigger problem, since no longer are there as many plants to anchor in the soil. In the northern Chinese province alone, 400 million are affected every year with an associated 54 billion yuan of annual economic loss due to grassland degradation. 
Story: The extensive grazing in Tibet lead to carbon and nitrogen loss, subject to desertification, while Nepal adopted a different approach to food production, putting nature and biodiversity first. 
Question: Which country experiences a lower level of desertification?

Ex Output:

Nepal.