Modern scientists divide the process of dying into two stages-clinical or te

游客2024-02-19  25

问题     Modern scientists divide the process of dying into two stages-clinical or temporary death and biological death. Clinical death occurs when the vital organs, such as the heart or lungs, have ceased to function, but have not suffered permanent damage. The organism can still be revived (复活). Biological death occurs when changes in the organism lead to the disintegration (解体) of vital cells and tissues. Death is then irreversible and final.
    Scientists have been seeking a way to prolong the period of clinical death so that the organism can be revived before biological death occurs. The best method developed so far involves cooling of the organism, combined with narcotic(麻醉的) sleep. By slowing down the body’s metabolism(新陈代谢), cooling delays the processes leading to biological death.
    To illustrate how this works, scientists performed an experiment on a six-year-old female monkey called Keta. The scientists put Keta to sleep with a narcotic. Then they surrounded her body with ice-bags and began checking her body temperature. When it had dropped to 28 degrees the scientists began draining blood from its body. The monkey’s blood pressure decreased and an hour later both the heart and breathing stopped; clinical death set in. For twenty minutes Keta remained in this state. Her temperature dropped to 22 degrees. At this point the scientists pumped blood into its body in the direction of the heart and started artificial breathing. After two minutes the monkey’s heart became active once more. After fifteen minutes, spontaneous breathing began, and after four hours Keta opened her eyes and lifted her head. After six hours, when the scientists tried to give her a penicillin injection, Keta seized the syringe and ran with it around the room. Her behavior differed little from that of a healthy animal. [br] The best statement of the main idea of this passage is that______.

选项 A、modern scientists divide the process of dying into clinical and biological death
B、biological death occurs when vital organs have suffered permanent damage
C、scientists have found a way to prolong the period of clinical death
D、cooling delays the processes leading to biological death

答案 C

解析 可定位在整篇文章,第1段解释了两种不同死亡阶段——临床死亡和生物死亡,第2段强调科学家们一直在寻找(have been seeking)一种方式来延长临床死亡的时间,通过冷却有机体和麻醉睡眠可实现,第3段描述对猴子Keta的具体实验过程,并在段首说明科学家们做此实验的目的是为了“illustrate how this works(举例说明上述结论是如何产生的)”,故正确选项为C,意为“科学家们已经找到一种方式来延长临床死亡时间”。
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