DOES the Yangtze River still have baiji（白鳍豚） the graceful grey dolphin with tiny eyes and a long narrow beak? Since November 6 a team of scientists from China Switzerland the United Kingdom the United States Germany and Japan have been searching for any sign of the freshwater dolphin on the middle and lower sections of the river. After six weeks they came back empty-handed. Wang Ding of the Chinese Academy of Sciences who is the head of the team said he has seen a sharp decline in the baiji population over the past few decades. However he is still unwilling to call the species extinct and adds “ We will try every effort to save them as long as they are not found to be extinct .” The baiji is shy and nearly blind and is one of the world’s oldest dolphin species. It dates back some 20 million years and is found only in the Yangtze. It's listed as one of the 12 most endangered animal species in the world. Around 400 baiji were believed to be living in the Yangtze until the 1980s. 1 A 1997 survey spotted 13. Two years later their numbers were down to two. The rapid disappearance of this dolphin over the past two decades coincided with the rapid expansion of economic development along the river. Research on some dead baiji collected in recent years showed that more than 90 per cent of the deaths were caused by human activities. One reason is that over-fishing has cut the dolphin's food sources. Dams built along the river and neighbouring waterways have also kept them from swimming into and out of their habitats (居住地). Meanwhile waste discharge (排放) has seriously polluted the river. And heavy river traffic has greatly reduced their living space. The disappearance of the baiji would be the first instance of a large aquatic (水生的) mammal being driven to extinction since hunting killed off the monk seal around 1952. 1．Which of the following statements is true? A．The baiji is already extinct. B．Man is mainly responsible for the sharp decline in the number of baiji. C．There are about 12 baijis now in China. D．Human activities make the baiji almost blind. 2．What does the underlined sentence mean? A．People don’t find out the fact that the baiji is already extinct. B．We shouldn’t give up saving the baiji despite its limited number. C．Our effort is worthless if we can’t protect the baiji. D．Effort will lead to more population growth of the baiji. 3．Monk seal is talked about in the last paragraph in order to show . A．baijis might be faced with the same threat as monk seals B．the monk seal is one of the large aquatic mammals C．mammals are more likely to be killed off D．the number of monk seals was very small 4．According to the passage all the measures to help save baiji are mentioned except . A．reducing the number of the ships traveling in the river B．building fewer dams along the river C．limiting and controlling the amount of fishing D．conducting more scientific research on the baiji
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【答案】 BBAD