共用题干 Screen Test1 Every year millions of women are screened with X-rays to pick up signs of breast cancer. If this happens early enough,the disease can often be treated successfully.According to a survey published last year,2 1 countries have screening pr

题目

共用题干
Screen Test

1 Every year millions of women are screened with X-rays to pick up signs of breast cancer. If this
happens early enough,the disease can often be treated successfully.According to a survey published last
year,2 1 countries have screening programs.Nine of them,including Australia,Canada,the US and Spain,
screen women under 50.
2 But the medical benefits of screening these younger women are controversial,partly because the
radiation brings a small risk of inducing cancer. Also,younger women must be given higher doses of X-rays
because their breast tissue is denser.
3 Researchers at the Polytechnic University of Valencia analyzed the effect of screening more than
160,000 women at 11 local clinics.After estimating the women's cumulative dose of radiation,they used
two models to calculate the number of extra cancers this would cause.
4 The mathematical model recommended by Britain's National Radiological Protection Board
(NRPB)predicted that the screening program would cause 36 cancers per 100,000 women,18 of them
fatal.The model preferred by the UN Scientific Committee on the Effects of Atomic Radiation led to a lower
figure of 20 cancers.
5 The researchers argue that the level of radiation-induced cancers is"not very significant"compared
to the far larger number of cancers that are discovered and treated.The Valencia program,they say,detects
between 300 and 450 cases of breast cancer in every 100,000 women screened.
6 But they point out that the risk of women contracting cancer from radiation could be reduced by
between 40 and 80 percent if screening began at 50 instead of 45,because they would be exposed to less
radiation.The results of their study,they suggest,could help"optimize the technique"for breast cancer
screening.
7 "There is a trade-off between the diagnostic benefits of breast screening and its risks," admits
Michael Clark of the NRPB.But he warns that the study should be interpreted with caution."On the basis of
the current data,for every 10 cancers successfully detected and prevented there is a risk of causing one later
in life.That'S why radiation exposure should be minimized in any screening program."

Early discovery of breast cancer may________.
A:be costly
B:harmful
C:save a life
D:still open to debate
E:reduce the risk of radiation triggering a cancer
F:reduced to the minimum

参考答案和解析

答案：C

解析：

由文章第二段内容可知：用X射线检查年轻女士是有争议的，部分原因是辐射有诱发癌症的危险。另外，年轻女士乳房组织紧密，给予的X射线的剂量要多一些，这对她们有害。
第三段的第一句话是这么说的：Valencia理工大学的研究人员分析了11个社区诊所用 X射线检查16万名以上女士的结果。这也是本段的主旨句。
第四段的主要内容是，两种不同的数学模型在预测用X射线检查女士诱发癌症方面的结果是不一样的。C项对这段话进行了概括。
由第五段第一句话“The researchers argue that the level of radiation-induced cancers is 'not very significant' compared to the far larger number of cancers that are discovered and treated.”可知，研究人员认为，与发现后接受治疗的癌症数字相比，由辐射诱发癌症的数字是微不足道的。
由文章第一段第二句“If this happens early enough, the disease can often be treated successfully.”可知，乳腺癌发现得早也许能挽救生命。
由文章第二段第一句“But the medical benefits of screening these younger women are controversial...”可知，用x射线检查年轻女士，就医学上的好处而论，是有争议的。
由文章第六段第一句话可知，延缓用x射线检查的年龄也许能减少辐射诱发癌症的危险。
由文章最后一段的末句“That' s why radiation exposure should be minimized in any screening program.”可知，F为正确答案。第4部分：阅读理解第一篇本篇文章主要讲述了轮班工作对工人身体健康的多种危害，同时建议人们怎样做以降低轮班工作的危害程度。

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