四级冲刺练习阅读（36）

　　Modern scientists divide the process of dying into two stages clinical or . Biological death occurs when changes in the organism lead to the disintegration 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 sleep. By slowing down the bodys metabolism , 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 an its body. The monkeys 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 monkeys 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.

　　26. This passage focuses on_______.

　　A. the difference between biological and clinical death.

　　B. the process of dying

　　C. prolonging the period of clinical death

　　D. the nature of clinical death

　　27. The best statement of the main idea of this passage is that

　　A. modem 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

　　28. One characteristic of clinical death is______.

　　A. lasting damage to the lungs B. destruction of the tissues

　　C. temporary non-functioning of the heartD. that the organism cannot be revived

　　29. According to the passage, cooling an organism

　　A. speeds up the bodys metabolism B. slows disintegration of body tissues

　　C. prevents damage to organs D. revives damaged organs

　　30. One possible benefit of the experiment discussed in the passage is______.

　　A. less crowded cities B. victory over death

　　C. protection against fatal injury D. fewer deaths from heart attacks

　　26. C 27. C 28. C 29. B 30. D