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。
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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).