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Modern scientists divide the process of dying into two phases —— clinical or temporary death and biological death.Clinical death occurs when the vital organs，such as the heart or lungs.have cease 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 “breaking up” of vital cells and tissues.Death is then unchangeable and final.

Scientists have been seeking a way to prolong the period of clinical death so that the organism can remain alive 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 scientist 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 artery （动脉）The monkey‘s blood pressure decreased and an hour later both the heart and respiration 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 an artery in the direction of the heart and started artificial respiration.After two minutes Keta’s heart become active once more.After fifteen minutes，spontaneous（自然产生的） respiration 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 （注射器） and ran with it around the room.Her behavior differed little from that of a healthy animal.

1.Which of the following statements about the person who suffers from the clinical death is true？

A.He still has the possibility of getting back to life.

B.He is dead forever.

C.Most of his important organs have been damaged permanently.

D.Most of the important organs can go on functioning with little damage

正确答案：A

2.Why do scientists try to make the time of clinical death longer？

A.They want to slow down the process of metabolism.

B.They want to bring the damaged cells and tissues back to life.

C.They want to delay the coming of biological death.

D.They want to save more time to cool the organs

正确答案：C

3.How did the scientists put the monkey into clinical death？

A.By pumping blood into an artery in the direction of the heart.

B.By surrounding her body with ice bags for a long time.

C.By stopping her respiration and draining her blood.

D.By putting her to sleep， lowering her temperature and draining her blood

正确答案：D

4.How long was Keta in the state of clinical death？

A.2 minutes.

B.20 minutes.

C.4 hours.

D.6 hours.

正确答案：B

5.What happened to the monkey when she was restored to the original state again？

A.Her metabolism was slower than ever before.

B.She was willing to have the penicillin injection.

C.She acted as lively as a healthy monkey.

D.Her heartbeat was not so strong as before

正确答案：C