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: Marine pollution is a generic term for the entry into the ocean of potentially hazardous chemicals or particles. The biggest culprits are rivers and with them many agriculture fertilizer chemicals as well as livestock and human waste. The excess of oxygen-depleting chemicals leads to hypoxia and the creation of a dead zone.Marine debris, which is also known as marine litter, describes human-created waste floating in a body of water. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter. 
Story: Two rivers, The Minninnippi and The Cedar, flow into the same ocean. The Minninnippi is surrounded almost entirely by farm lands due its location in a flat area of the country that sees regular rainfall. The majority of these farms will have runoff from their crop soil flow into the river. The Cedar is located mostly inside an unpopulated forest. Currently, not much industrialization or settling by humans has happened near The Cedar. 
Question: Is it more or less likely that the ocean water near The Cedar will experience hypoxia?

Answer: less.


Question: Background Paragraph: The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to loss of deltaic wetlands. 
Story: Jill lives out in a peaceful quiet area with hardly any other people around. Next to her home is a calm peaceful river. The river doesn't have an official name that she is aware of, but her family has always called it River Treetop due to the large tree next to it. Also next to her house, there is a roaring river that runs for miles. The river is so loud that it can be hard to hear yourself think sometimes if you are sitting next to it. For this reason, Jill has always referred to the river as River Chaos. 
Question: Is the biodiversity in River Treetop higher or lower than in River Chaos?

Answer: lower.


Question: Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: The Berg mountains in Berg county are of a volcanic nature, very massive, few caves. The Gorge mountains in Gorge county are made of sedimentary rocks, predominantly limestone. They were exposed to water and that lead to karst lanscapes, caves, blue holes, stalactites and stalagmites. 
Question: Which of the two mountains eroded slower over time?

Answer:
Berg.