20、
第四部分：阅读理解(每题3分，共45分， 建议40分钟以内完成)
下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案涂在答题卡相应的位置上。
难度B/C级
Cigars Instead
Smoking one or two cigars a day doubles the risk of cancers of the lip，tongue，mouth，and throat，according to a government study.
Daily cigars also increase the risk of lung cancer and cancer of the esophagus，and increase the risk of cancer of the larynx(voicebox)sixfold ，say researchers at the National Cancer Institute in Bethesda，Maryland.
In addition，the report revealed that smoking three or four cigars a day increased the risk of oral cancer to 8.5 times the risk for nonsmokers and the risk of esophageal cancer by four times the risk of nonsmokers.
The health effects of smoking cigars is one of eight sections of the article“Cigars：Health Effects and Trends.”The researchers report that，compared with a cigarette，a large cigar emits up to 90 times as much carcinogenic tobacco-specific nitrosamines. "This article provides clear and invaluable information about the disturbing increase in
cigar use and the significant public health consequences4 for the country，”said Dr.Richard Klausner director of the National Cancer Institute，in a statement.
“The data are clear—the harmful substances and carcinogens in cigar smoke，like
cigarettes，are associated with the increased risks of several kinds of cancers as well as heart and lung diseases.”he added.“In other words，cigars are not safe alternatiyes to cigarettes”and may be addictive.”
“To those individuals who may be thinking about smoking cigars,our advice is—don’t.To those currently smoking cigars,quitting is the only way to eliminate completely the cancer， heart and 1ung disease risks，”warned K1ausner.
According to a National Cancer Institute press release，there haven’t been any studies on the health effects on nonsmokers at cigar social events，but“…a significant body of evidence clearly demonstrates all increased lung cancer risk from secondhand smoke.”
练习：
1.According co the report,smoking three orfour cigars a day
A)increases the risk of oral cancer for non-smokers.
B)greatly increases the risk of oral cancer for smokers.
C)increases the risk of more than one cancer for non-smokers，
D)greatly increases the risk of more than one cancer for smokers.
2.In the passage how many cancers are mentioned in relation to smoking cigars daily?
A)Six.
B)Seven.
C)Eight.
D)Nine.
3.What is the main idea of the article“Cigars：Health Effects and Trends”?
A)Whenitcomesto cancer，cigars arenotany saferthan cigarettes.
B)Cigars may be addictive while cigarettes are not easily so.
C)Cigars contain less harmful substances than cigarettes.
D)Increase in cigar-smoking does not affect public health much.
4.What is the doctors’advice to those cigar-smokers?
A)To give it up completely.
B)Togiveuppartofit.
C)Not to think about it any more.
D)To cure the diseases first.
5.In the context of this passage,“secondhand smoke”means
A)smoking bad-quality cigars.
B)smoking very cheap cigars.
C)being near cigar smokers when they are not smoking.
D)being near cigar smokers when they are smoking.
标准答案： D,B,A,A,D
21、
难度B/A级
High Stress May Damage Memory
According to a report issued in May 1998，elderly people who have consistently high blood levels of cortisol don’t score as well on memory tests as their peers with 10wer levels of the stress hormone.What’s more.high 1evels of cortisol are also associated with shrinking of the hippocampus，a region of the brain that plays a key role in learning and memory.
The findings suggest that even cortisol levels in the normal，“healthy”range can actually accelerate brain aging.
The study results“now provide substantial evidence that long—term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans，”write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial.Cortisol is a hormone released in response to stress by the adrenal glands，which sit on top of the kidneys.
Over a 5 to 6-year period，Dr.Sonia Lupien and his colleagues measured 24-0hour cortiso1 levels in 51 healthy volunteers，most of Whom were in their 70s.
Despite wide variation in cortis01 levels.the participants could be divided into three subgroups：those whose cortisol progressively increased over time and was currently high (increasing/high);those whose cortisol progressively increased over time and was currently moderate(increasing/moderate);and subjects whose cortisol decreased, but was currently moderate(decreasing/moderate).
The researchers tested the volunteers’memory on six people in the increasing/high category and five people in the decreasing/moderate group.The groups did not differ on tests of immediate memory，but the increasing/high cortisol group had other memory problems compared with those in the decreasing/moderate group.
The researchers also found that the total volume of the hippocampus in those in the increasing/high group was 14%lower than those in the decreasing/moderate group, although there were no differences in other brain regions.
The results suggest that“…brain aging Can be accelerated by levels of adrenal hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging，”write Porter and Landfield.“This further suggests that chronic stress may accelerate the worsening of hippocampus.”
练习：
1. The part of the brain important for a person’s learning and memory is
A)the cortiso1.
B)the adrenal glands.
C)the stress hormones
D)the hippocampus.
2.When the levels of cortisol go higher，the hippocampus in the brain may
A)become larger.
B)become smaller.
C)disappear completely.
D)be totally damaged.
3.According to the article，when people feel too worried or nervous or when they overwork，
A)the adrenal glands will produce a stress hormone.
B)the kidneys will produce adrenal glands.
C)the hippocampus will produce high levels of cortisol in the blood.
D)the brain will work more effectively.
4.It appears that when the total volume of the hippocampus becomes smaller as a result of high blood levels of cortisol，other brain regions
A) become smaller too.
B)become larger.
C)may remain the same in size.
D)maybe damaged.
5.The research conducted by Porter and Landfield shows that
A)changes in the levels of adrenal hormones have nothing to do with brain aging
B)changes in the levels of adrenal hormones may affect brain aging.
C)chronic stress may strengthen a man’s memory.
D)the rate of brain aging always remains stable.
标准答案： D,B,A,C,B
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