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  3. WELL—do they or don’t they? For years, controversy has raged over whether the electromagnetic fields produced by power lines cou

WELL—do they or don’t they? For years, controversy has raged over whether the electromagnetic fields produced by power lines cou

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问题     WELL—do they or don’t they? For years, controversy has raged over whether the electromagnetic fields produced by power lines could cause cancer especially leukemia in young children. But in Britain last week confusion reached new heights.
    One team from Bristol announced that it had evidence to back a controversial but plausible theory which would explain how power lines might cause cancer(electric fields attract airborne pollutants). Only to be followed by the release of results by another group in London which suggested there is nothing to worry about. What is going on?
    Actually, the confusion may be more apparent than real. There can be no doubt that the effects of power lines on water droplets, pollutants and naturally occurring radon uncovered by the Bristol team are real and interning. But to suggest that they have anything to do with leukemia in children is premature. The extra exposure to pollution for a child living near power lines would be tiny, and it is not obvious why radon, a gas normally associated with lung cancer—would cause leukemia in children.
    The second study, which drew reassuring blank, is the world’ s biggest ever probe of the statistical link between childhood cancers and magnetic fields of the sort produced by power lines and electrical appliances. It is one of several recent studies that have failed to find a link.
    Unlike earlier research, these newer studies involved going into homes to measure the electromagnetic fields. The fields they measured included input from major power lines if they were.
    Which is not to say the research is perfectly. Critics argue that Britain’ s childhood cancer study, for example, has not yet taken into account the surges in exposure that might come from, say, switching appliances on and off. And some people might wonder why measurements of the electric fields that are also produced by power lines did not figure in last week’ s study. But neither criticism amounts to a fatal blow. Electrical fields cannot penetrate the body significantly, for example.
    A more serious concern is whether the British research provides an all-clear signal for such countries as the US where power lines carry more current and therefore produce higher magnetic fields. Pedants(书呆子)would conclude that it doesn’ t. But these counties will not have long to wait for answers from a major Japanese study.
    In Britain the latest epidemiological study can be taken as the final word on the matter. If the electromagnetic fields in British homes can in some unforeseen way increase the risk of cancer, we can now be as certain as science allows that the increase is too tiny to measure.
What can be suggested from the results of the second study?
选项 A、There does exist a danger zone near power lines.
B、There is much to be improved in terms of design.
C、There is nothing to worry about as to power lines.
D、There is no link between the first and second study.
答案C
解析 第四段提到第二组研究failed to find a link between childhood cancers and magnetic fields of the sort produced by power lines and electrical appliances．他们找不到儿童期癌症与输电线和电气设备产生的磁场之间的联系。这就暗示着不必担心输电线会产生什么危害。
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