共用题干

共用题干
Chimpanzees
1 Chimpanzees（黑猩猩）will soon be extinct（灭绝）.If the present rate of hunting and habitat（栖息地）destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy（悲剧）.Chimpan-zee extinction may also have profound implications（含意）for the survival of their distant relatives一human beings.
2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes（基因组）match by ovet 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority（优先）.But there is another,more selfish reason to preserve the chimp.
3 The chimpanzees' trump card（王牌）comes in the field of medical research. Chimpanzees are so similar to humans that veterinarians（兽医）often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.
4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-dlined because they are so resistant.
5 By sequencing the chimp genome and pinpointing（找到）the place where the chimpanzee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the alteration（改变）of the human genetic sequence. The recently completed human genome sequencing project has shown that such an effort is now well within our reach.

Paragraph 2______
A: Reasons for HIV Resistance
B: Implications of Chimpanzee Extinction for Humans
C: Effective AIDS Treatment
D: Genetic Similarities Between Chimps and Humans
E: Chimps'Resistance to HIV
F: Genetic Differences Between Chimps and Humans