--You didn't attend the party last night?--No, I__________, for the party was put off for some reason.
A．couldn't haveB．needn't haveC．didn't need toD．don't have to

请阅读Passage 1，完成题：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 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.According to the passage, cooling an organism__________.查看材料
A．speeds up the body's metabolismB．slows disintegration of body tissuesC．prevents damage to organsD．revives damaged organs

请阅读Passage 1，完成题：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 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.One possible benefit of the experiment discussed in the passage is__________.查看材料
A．less crowded citiesB．victory over deathC．protection against fatal injuryD．fewer deaths from heart attacks

He was fired because of his __________ refusal to follow orders.
A. obstinateB. obstructiveC. obedientD. obsessive

For better classroom management, what should the teacher do while the students are doing activities?
A. Participating in a group.B. Preparing for the next procedure.C. Moving around to monitor, prompt and provide help.D. Standing in front of the class.

请阅读Passage 1，完成题：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 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.The best statement of the main idea of this passage is that__________.查看材料
A．scientists have found a way to prolong the period of clinical deathB．biological death occurs when vital organs have suffered permanent damageC．modern scientists divide the process of dying into clinical and biological deathD．cooling delays the processes leading to biological death