第三部分阅读理解（共20小题，每小题2分，满分40分）
阅读下列短文，从题中所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。                 
Scientists in Canada say big ocean fish have almost disappeared from the world since the start of industrial fishing in the 1950s. The scientists found the populations of large fish like tuna(金枪鱼), swordfish and cod（鳕鱼） have dropped by ninety percent in the past fifty years.
The study took ten years. The researchers gathered records from fishing businesses and governments around the world. The magazine Nature published the findings.
The scientists say the common method called long line fishing is especially damaging to populations of large fish. This method involves many fishing lines connected to one boat. These wires can be nearly one hundred kilometers long. They hold thousands of sharp metal hooks to catch fish.
Long line fishing is especially common in the Japanese fishing industry. Records showed that Japanese boats used to catch about ten fish for every one hundred hooks. But long line fishing boats now might only catch one fish per hundred hooks.
The scientists say industrial fishing can destroy groups of fish much faster than in the past. The study suggests that whole populations can disappear almost completely from new fishing areas within ten to fifteen years.
Ransom Myers and Boris Worm of Dalhousie University in Nova Scotia led the study with the University of Kiel in Germany. Worm says the destruction could lead to a complete reorganization of ocean life systems. Meyers says the decreased numbers of large fish are not the only worry. He says even populations that are able to reproduce do not get the chance to live long enough to grow as big as their ancestors. He says not only are there fewer big fish, but also they are smaller than those of the past.
American government scientists say even with the best efforts to protect fish populations, decreases are to be expected.
56. Which one can be the best title for the passage?
A. Discoveries Canadian scientists have made      B. Japan fishing industry
C. Losses of big fish                          D. Modern fishing methods
57. When did the researchers begin to survey the decrease of large fish?
A. in the 1960s      B. in the 1970s       C. in the 1980s              D. in the 1990s
58. The underlined word “sharp” in Para 3 means _________.
A. having a fine edge or point that can cut or make a hole in something
B. sudden or rapid change in something
C. quick to react or to understand things
D. loud, sudden and often high in tone
59. Which of the following statements can show the fact that the populations of large fish have dropped?
A. Today’s “large” fish are smaller than those of the past.
B. Long line fishing boats now might catch ten fish for every one hundred hooks.
C. Fish able to reproduce don’t have the chance to live longer.
D. Long line fishing boats now might catch one fish for every one hundred hooks
60. Where is the passage probably taken from?
A. A story book      B. A business magazine         C. An environmental report      D. An economic survey