单选题 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. 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 that the organism can be revived before biological death
occurs. The best method developed so far involves cooling of the organism,
combined with narcotic sleep. By slowing down the body's metabolism, cooling de-
lays 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 tour 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.
单选题
This passage focuses on ______.
A. the difference between biological and clinical death
单选题
The best statement of the main idea of this passage is that ______.
A. scientists have found a way to prolong the period of clinical death
B. biological death occurs when vital organs have suffered permanent
damage
C. modern scientists divide the process of dying into clinical and
biological death
D. cooling delays the processes leading to biological death
【正确答案】
A
【答案解析】[解析] A项“科学家已找到延长临床死亡的办法”最能够体现全文主旨。
单选题
One characteristic of clinical death is ______.
A. lasting damage to the lungs
B. destruction of the tissues
C. temporary non-functioning of the heart
D. that the organism cannot be revived
【正确答案】
C
【答案解析】[解析] 根据第一段“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.”可知，临床死亡是指机体的重要器官比如心、肺等停止运转，但是还没有遭到永久的损害，机体还可以复活。因此答案为C。
单选题
According to the passage, cooling an organism ______.
A. speeds up the body's metabolism
B. slows disintegration of body tissues
C. prevents damage to organs
D. revives damaged organs
【正确答案】
B
【答案解析】[解析] 根据第二段“By slowing down the body's metabolism,cooling delays the processes leading to bio1ogical death.”以及第一段可知，生物死亡是指机体的变化导致了重要细胞和组织的瓦解，冷冻减慢了机体新陈代谢的过程，因此也就延缓了通往生物死亡的过程，即延缓了机体组织瓦解的过程，因此答案为B。
单选题
One possible benefit of the experiment discussed in the passage is
______.