About 3 billion people live within 100 miles of the sea, a number that could double in the next decade as humans flock to coasta

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问题     About 3 billion people live within 100 miles of the sea, a number that could double in the next decade as humans flock to coastal cities like gulls. The oceans produce $3 trillion of goods and services each year and untold value for the Earth’s ecology. Life could not exist without these vast water reserves—and, if anything, they are becoming even more important to humans than before.
    Mining is about to begin under the seabed in the high seas—the regions outside the exclusive economic zones administered by coastal and island nations, which stretch 200 nautical miles offshore. Nineteen exploratory licences have been issued. New summer shipping lanes are opening across the Arctic Ocean. The genetic resources of marine life promise a pharmaceutical bonanza: the number of patents has been rising at 12% a year. One study found that genetic material from the seas is a hundred times more likely to have anti-cancer properties than that from terrestrial life.
    But these developments are minor compared with vaster forces reshaping the Earth, both on land and at sea. It has long been clear that people are damaging the oceans—witness the melting of the Arctic ice in summer, the spread of oxygen starved dead zones and the death of coral reefs. Now, the consequences of that damage are starting to be felt onshore.
    Thailand provides a vivid example. In the 1990s it cleared coastal mangrove swamps to set up shrimp farms. Ocean storm surges in 2011, no longer cushioned by the mangroves, rushed in to flood the country’s industrial heartland, causing billions of dollars of damage.
    More serious is the global mismanagement of fish stocks. About 3 billion people get a fifth of their protein from fish, making it a more important protein source than beef. But a vicious cycle has developed as fish stocks decline and fishermen race to grab what they can of the remainder. According to the Food and Agriculture Organization (FAO), a third of fish stocks in the oceans are over-exploited; some estimates say the proportion is more than half. One study suggested that stocks of big predatory species—such as tuna, swordfish and marlin—may have fallen by as much as 90% since the 1950s. People could be eating much better, were fishing stocks properly managed.
We can learn from the last paragraph that ______.

选项 A、a fifth of people in the world get their protein from fish
B、FAO predicts that a third of ocean resources are over-exploited
C、many predatory species in the ocean have disappeared since 1950s
D、the number of fish has fallen greatly because of human exploitation

答案D

解析 选项A对应最后一段第二句:About 3 billion people get a fifth of their protein from fish…该句说的是“About 3 billion people”,而不是“a fifth of people in the world”。故该项属于偷换概念,因此该项错误。选项B对应中间一句:According to the Food and Agriculture Organization(FAO),a third of fish stocks in the oceans are over-exploited…注意:原文说的是“a third of fish stocks”,而不是该项说的“a third of ocean resources”,故该项也是偷换概念的错误。选项C对应该段倒数第二句:One study suggested that stocks of big predatory species—such as tuna,swordfish and marlin—may have fallen by as much as 90% since the 1950s.注意:原文说的是“fallen by as much as 90%”,而不是该项说的“disappeared”,故该项错误。选项D同样对应倒数第二句。从中可以判断,该项表述正确,故答案为选项D。
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