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: 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 Gorge saw some negative effects due to deforestation. The Valley has a more fertile soil, it's not overgrazed, and the trees and bushes are abundant, and the productivity has increased several fold over the past decade. Biodiversity in the Valley is varied, and the soils are nutritious and retain more water, nitrogen and carbon. 
Question: Which area experiences less soil erosion?

A: The Valley.
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Q: Background Paragraph: The balls used in squash are small rubber balls that can differ in terms of diameter, weight and softness. These features determine the speed and bouncing amplitude of the ball, with softer balls being generally slower than the harder balls. The temperature of the ball also affects the amount of bounce: the warmer the ball, the more it bounces.[3] Because cold squash balls have little bounce, the squash balls are hit multiple times at the beginning of a game to warm them up. It also means that a game becomes gradually faster as it advances and that softer balls may be too slow to be used in colder climates.[4]. 
Story: Thomas and Joseph, two experienced squash players, are having a disagreement about which types of squash balls they should use in their match. Both have different preferences for the type of ball used. Joseph prefers a ball that bounces less and travels more slowly. Thomas, on the other hand, prefers a ball that travels more quickly and bounces more. 
Question: Which player enjoys the speed of game more as it progresses?

A: Thomas.
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Q: Background Paragraph: Another example of incomplete dominance is with sickle cell anemia, a disease in which a blood protein called hemoglobin is produced incorrectly. This causes the red blood cells to have a sickle shape, making it difficult for these misshapen cells to pass through the smallest blood vessels. A person that is homozygous recessive ( ss ) for the sickle cell trait will have red blood cells that all have the incorrect hemoglobin. A person who is homozygous dominant ( SS ) will have normal red blood cells. 
Story: Two sisters named Mary and Ann went in for a blood test and found out that Mary had sickle cell anemia. Ann was normal. 
Question: Which sister wasn't homozygous recessive?

A:
Ann.
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