以下是引用qiqi_cola在2003-9-23 22:54:00的发言:砖头:p176 Radioactive radon gas emanating from rock such as granite puts inhabitants of houses built on such rock at greater risk of lung cancer the longer the inhabitants are exposed. Protective steps should be taken if radon measurements exceed 4 picocuries per liter; this recommendation is based on 70 years of occupancy by any one person. If a 65-year-old homeowner concludes from the information above that radon testing for the new home she has purchased will not be necessary,then each of the following,if ture, weakens the homeowner's argument EXCEPT: A Houses in which the homeowner previously lived were in an area where elevated radon levels have been found. 我觉的这个答案跟题目无关啊。
此题出自93年GRE,答案应该是(E): The strata underlying the homeowner's new home are known to be of rock different from the kinds from which radon emanates.
其他所有的选项都在削弱。你可以把书上的答案更正过来。有问题再来讨论。
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