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: Often, foreign exchange controls can result in the creation of black markets to exchange the weaker currency for stronger currencies. This leads to a situation where the exchange rate for the foreign currency is much higher than the rate set by the government, and therefore creates a shadow currency exchange market. As such, it is unclear whether governments have the ability to enact effective exchange controls.[1]. 
Story: In the beginning of this century there was scandal in the financial market regarding black market trading. A trader named Trader A was working for Bank A. He noticed country M has pegged its currency to a fixed price while country N did not do that. He opted to trade country M currency. Across the aisle his colleague trader B was working for bank B. He traded country N's currency. 
Question: Would country N's currenccy be traded or not traded in the balck market?

A: not traded.
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Q: 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?

A: less.
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Q: Background Paragraph: A baby is born with zones of cartilage in its bones that allow growth of the bones. These areas, called growth plates , allow the bones to grow longer as the child grows. By the time the child reaches an age of about 18 to 25 years, all of the cartilage in the growth plate has been replaced by bone. This stops the bone from growing any longer. Even though bones stop growing in length in early adulthood, they can continue to increase in thickness throughout life. This thickening occurs in response to strain from increased muscle activity and from weight-lifting exercises. 
Story: Two brothers, Tom, aged 26, and Paul, aged 16, started weight-lifting to gain more muscle mass. Three years later they were 20-25 lbs. heavier. 
Question: Which brother had active growth cartilages?

A:
Paul.
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