4. B。主旨题。第二段的第一、二句The most widespread mistake of all is that colds are caused by cold. They are not.是本文的主题句。全文主要阐述了“感冒不是由寒冷引起的”这一观点。

(14)

 Zinc(锌) is one of about 20 elements necessary for good health. It is present in the body in a very small amount but makes it possible for important chemical actions to be carried out in cells. Scientists are just beginning to discover how zinc and other elements work.

 Researchers first studied zinc as a way to speed recovery. Dr. Waltor Powys formerly with the United States Air Force noted that the laboratory animals recovered faster when some matters were added to their food. One of these matters was zinc. Dr. Powys later tested the zinc treatment on an American airman recovering from medical operations. The airman who received zinc sulphate(硫酸盐) recovered in half of the usual time. Other doctors studied persons who had a number of strange disorders. The doctors learned that all of these problems were caused by lack of zinc in the body. They treated these disorders successfully by giving the patients zinc sulphate.

 The amount of zinc in the body can be found by examining blood and hair. A lack of this important element is not uncommon among people in both industrial and developing countries. Zinc is found in most high protein(蛋白质) foods such as meat, milk, fish and eggs. It is also found in whole grains. But many people do not eat enough of these food. Food markets should add these elements so that more people could get needed amount of these necessary matters.

5. C。推断题。根据 However, traffic often returns to full speed within months as drivers become used to seeing the painted bars 可知。

 (13)

The common cold is the world's most widespread illness, which is plagues(疫病) that flesh receives.

The most widespread mistake of all is that colds are caused by cold. They are not. They are caused by viruses(病毒) passing on from person to person. You catch a cold by coming into contact, directly or indirectly, with someone who already has one. If cold causes colds, it would be reasonable to expect the Eskimos to suffer from them forever. But they do not. And in isolated Arctic regions explorers have reported being free from colds until coming into contact again with infected people from the outside world by way of packages and mail dropped from airplanes.

During the First World War soldiers who spent long periods in the trenches(战壕), cold and wet, showed no increased tendency to catch colds.

In the Second World War prisoners at the notorious Auschwitz concentration camp(奥斯维辛集中营), naked and starving, were astonished to find that they seldom had colds.

At the Common Cold Research Unit in England, volunteers took part in Experiments in which they gave themselves to the discomforts of being cold and wet for long stretches of time. After taking hot baths, they put on bathing suits, allowed themselves to be with cold water, and then stood about dripping wet in drafty room. Some wore wet socks all day while others exercised in the rain until close to exhaustion. Not one of the volunteers came down with a cold unless a cold virus was actually dropped in his nose.

If, then, cold and wet have nothing to do with catching colds, why are they more frequent in the winter? Despite the most pains-taking research, no one has yet found the answer. One explanation offered by scientists is that people tend to stay together indoors more in cold weather than at other times, and this makes it easier for cold viruses to be passed on.

No one has yet found a cure for the cold. There are drugs and pain suppressors(止痛片) such as aspirin, but all they do is to relieve the symptoms(症状). 

 0  250498  250506  250512  250516  250522  250524  250528  250534  250536  250542  250548  250552  250554  250558  250564  250566  250572  250576  250578  250582  250584  250588  250590  250592  250593  250594  250596  250597  250598  250600  250602  250606  250608  250612  250614  250618  250624  250626  250632  250636  250638  250642  250648  250654  250656  250662  250666  250668  250674  250678  250684  250692  447348 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网