阅读理解(48分)

　　One night, a little before nine o’clock, Dr. Van Eyck answered his telephone.

　　“We have a very sick boy here. We should operate at once. But we haven’t got a surgeon (外科医生) here at the time.”

　　“I’m 60 miles from your hospital,” said Dr. Van Eyck. “And it’s snowing here. But I’ll try to get there before 12 o’clock.”

　　“I should tell you that the boy’s family is very poor. I don’t think that they can pay you anything.”

　　“That’s all right,” said Dr. Van Eyck.

　　A few minutes later, the doctor’s car had to stop for a red light. A man in an old black coat opened the door of the car and got in.

　　“Drive on,” he said. “I’ve got a gun.”

　　“I’m a doctor,” said Van Eyck. “I’m on my way to the hospital to operate on a very sick…”

　　“Don’t talk, just drive.”

　　A mile out of town he ordered the doctor to stop the car and get out. Then the man drove on down the road. The doctor stood there for a moment in the falling sow.

　　It was after two o’clock in the morning when the surgeon arrived at the hospital.

　　“I did my best,” said Dr. Van Eyck, “but I was stopped on the road and my car…”

　　“It was good of you to try. The boy died an hour ago.”

　　He walked by the door of the hospital waiting room. There sat the man in the old black coat, with his head in his hands.

　　“Mr. Cunningham,” said a nurse to the man, “this is Dr. Van Eyck. He is the surgeon who came all the way from his town to try to save your boy.”

　　( ) 46. The doctor was late because .

　　A. it was snowing hard all the way B. he lived 60 miles away from the hospital

　　C. his car was stopped on the road D. his car was driven away by someone

　　( ) 47. The very sick boy who needed to be operated on couldn’t have died if .

　　A. it wasn’t snowing that night B. the doctor hadn’t stopped for that red light

　　C. the doctor had arrived at one o’clock in the morning

　　D. the man in the old black coat had known the doctor

　　( ) 48. Which of the following is NOT true?

　　A. Mr. Cunningham was the sick boy’s father.

　　B. Mr. Cunningham was the man in an old black coat.

　　C. Mr. Cunningham robbed the doctor of his car.

　　D. Mr. Cunningham took the doctor’s car as his own.

　　( ) 49. The man in an old black coat got into the doctor’s car .

　　A. at a crossing in town B. at a crossing out of town

　　C. a mile out of town D. halfway to the hospital

　　In the summer of 1897 an English doctor, Ronald Ross, worked in a field hospital in India. Ross set out to find the cause of malaria (疟疾). Ross observed that patients in the field hospital who did not have malaria were more likely to develop the deadly disease in the open wards (病房) than in wards with closed windows or screens. Ross suggested a hypothesis (假设): mosquitoes (蚊子) in the open wards might be spreading the disease from patients with malaria to patients who did not have the disease.

　　Ross predicted (预言) that if mosquitoes were spreading malaria (hypothesis) , then mosquitoes that had bitten malaria patients and sucked up some of their blood should have picked up the parasite (寄生虫) (prediction) , which is always present in the blood of malaria victims (受害人). Ross also predicted that parasites should be alive within the mosquito. Somehow the parasites make their way from the mosquito’s stomach to its saliva (唾液) so that the parasites are transferred (迁移) with the mosquito’s saliva to the next person bitten. So if a person is bitten by a malaria-carrying mosquito, that person will receive some of the parasite in the saliva left behind by the mosquito.

　　Ross looked for living malaria parasites in mosquitoes that had bitten malaria patients. He carefully dissected (切开) the mosquito’s stomach and found the live parasites.

　　Ross carried out a control experiment, in which the condition suspected (怀疑) to cause this is compared to the same situation without the suspected condition ( a control group), Nothing else is changed in any way. In Ross’s experiment, the suspected condition was mosquitoes feeding on malaria victims. As a control, Ross checked mosquitoes that had not bitten someone with the disease to see if they also contained (包含) the parasite. Gathering mosquitoes that had not yet fed, he allowed them to feed on malaria-free blood, and then he examined them. Their stomachs and saliva lacked (缺乏) the parasite. The control group of mosquitoes did not contain malaria parasite. The experiments proved, that Ross’s hypothesis was correct.

　　Ross’s theory that malaria is transferred by mosquitoes carrying it from one person to another was in important milestone (里程碑) in medicine. Finding the cause of malaria is one of the greatest medical advances of all time.

　　( ) 50. Working in a field hospital, Ross observed were more likely to develop malaria.

　　A. patients in the field hospital B. patients who did not have malaria

　　C. patients in the open wards D. patients in wards with closed windows and screens

　　( ) 51. Ross’s hypothesis was that .

　　A. mosquitoes in the open wards might be spreading malaria

　　B. mosquitoes that had bitten malaria patients should have picked up the parasite

　　C. parasite is always present in the blood of malaria victims

　　D. parasite should be alive within mosquitoes that had bitten malaria patients

　　( ) 52. Which of the following is the way of mosquitoes’ spreading malaria?

　　A. blood of malaria victims → mosquitoes’ stomach → blood of another patient

　　B. parasite → mosquitoes’ stomach → mosquitoes’ saliva

　　C. patients with malaria → blood → parasite → blood

　　D. malaria patients → mosquitoes → person bitten by mosquitoes

　　( ) 53. In Ross’s control experiment .

　　A. the condition suspected to spread malaria was mosquitoes feeding on malaria patients

　　B. mosquitoes that hadn’t bitten any malaria victims also contained the parasite

　　C. mosquitoes were allowed to feed on blood of malaria patients

　　D. the stomachs and saliva of the control group of mosquitoes did not lack the parasite

　　The human body naturally prevents attempt (企图) to lose or gain weight. Thus the best way to lower your weight is to do some exercise daily. Although scientists don’t agree exactly how this works to lower the "setpoint", they do know that exercise helps your body work with you and not against you in at least the following ways:

　　1. Exercise burns calories (卡路里): if you walk two miles every day, you use an extra 1400 calories a week - and lose about a pound in two weeks.

　　2. Exercise helps to burn fat and build muscle: since muscle requires more calories than fat does, the more muscle you have, the faster you will burn calories.

　　3. Finally exercise speeds up your metabolism (新陈代谢) not just while you’ re exercising, but for several hours after exercise ends.

　　A program of light-to-moderate exercise done for only a half-hour a day is enough to keep your "setpoint" lowered, and thus helps you lose weight and keep it off. If you need to lose more than five pounds, combine regular exercise with a moderate reduction in calories until you reach your goal (目标).

　　( ) 54. Scientists don’t .

　　A. believe in exercise at all B. agree exercise helps to lower people’s weight

　　C. think exercise helps people’s bodies work against them

　　D. think exercise helps people’s bodies work with them

　　( ) 55. Exercise helps you .

　　A. save calories and gain weight B. save calories but lose weight

　　C. bum calories and lose weight D. bum calories but gain weight

　　( ) 56. When you walk .

　　A. slowly, the fat in your body increases B. fast, the fat in your body reduces

　　C. faster, you bum less calories D. less, you build more muscles

　　( ) 57. Which of the following is NOT true?

　　A. A man of more muscles bums calories faster.

　　B. Exercise speeds up your metabolism even after it.

　　C. An hour and a half’s exercise is not enough to keep your "setpoint" lowered.

　　D. To lose more than 5 pounds, just doing exercise is not enough.