【B1】____The major reason is loss of habitat, which has continued despite th

游客2024-08-11  13

问题      【B1】____The major reason is loss of habitat, which has continued despite the establishment of 14 panda reserves. Deforestation, mainly carried out by farmers clearing land to make way for fields as they move higher into the mountains, has drastically contracted the mammal’s range. The panda has disappeared from much of central and eastern China, and is now restricted to the eastern flank of the Himalayas.
     【B2】____ Almost half of the panda’s habitat has been cut down or degraded since 1975. Worse, the surviving panda population has also become fragmented: a combination of satellite imagery and ground surveys reveals panda "islands" in patches of forest separated by cleared land. The population of these islands has become isolated because the animals are loath to cross open areas. Just putting a road through panda habitat may be enough to split a population in two.
     【B3】____The smallest groups have too few animals to be viable, and will inevitably die out. The larger populations may be viable in the short term, but will be susceptible to genetic defects as a result of inbreeding.
     【B4】____The flowering prompts pandas to move from one area to another, thus preventing inbreeding in otherwise sedentary populations. In panda islands, however, bamboo flowering could prove catastrophic(灾难性的)because the pandas are unable to emigrate.
    The latest conservation management plan for the panda, prepared by China’s Ministry of Forestry and the World Wide Fund for Nature, aims primarily at maintaining panda habitats and ensuring that populations are linked wherever possible. This plan will change some existing reserve boundaries , establish 14 new reserves and protect or replant corridors of forest between panda islands. Other measures include better control of poaching, reducing the degradation of habitats outside reserves, and reforestation.
     【B5】____Implementation will be expensive and will require participation by individuals ranging from villagers to government officials.
Questions 61 to 65
Choose from the sentences A—G the one which best fits each gap of 61—65. There are two extra sentences which you do not need to use.
A. The plan is ambitious.
B. The giant panda, the creature that has become a symbol of conservation, is facing extinction.
C. Satellite imagery has shown the seriousness of the situation.
D. In these circumstances, a more traditional threat to pandas—the cycle of flowering and subsequent withering of the bamboo that is their staple food—can become literally species-threatening.
E. The minuscule size of the panda populations worries conservationists.
F. Panda is one of the rarest animals in China.
G. It’s impossible to achieve this goal. [br] 【B4】

选项

答案 D

解析 本段主要讲了竹子的繁殖对熊猫的影响,D选项“竹子的枯萎是威胁熊猫生存的又一大因素”放在此处能使上下语意连贯。
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