2. 外语
  3. Scientists who believe cell phones are dangerous have been throwing out hypotheses to explain away the negative results. Maybe s

Scientists who believe cell phones are dangerous have been throwing out hypotheses to explain away the negative results. Maybe s

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问题     Scientists who believe cell phones are dangerous have been throwing out hypotheses to explain away the negative results. Maybe something about the【C1】______animals raised their rates of cancer or sperm problems, so【C2】______the exposed animals didn’t seem to be harmed. Maybe the studies should have used pulsed,【C3】______radiation rather than a continuous beam, the better to【C4】______the way we actually use mobile phones. Maybe it matters【C5】______the lab animals are zapped【C6】______in a device like a Ferris wheel or while【C7】______around in cages. On the other hand, if these details do【C8】______, maybe that in itself is significant.
    Scientists who【C9】______claims that cell-phone radiation is causing an epidemic of brain cancer【C10】______that there isn’t any mechanism.【C11】______textbook biophysics, only radiation that has enough energy to ionize molecules—that is, knock off electrons—can【C12】______cancer. Cell phones don’t【C13】______energy great enough to ionize molecules in living cells. Their【C14】______is "far below the cancer energy threshold,"【C15】______physicist Robert Park of the University of Maryland, who often【C16】______junk science. But whenever he makes that【C17】______in his What’s New e-newsletter, he gets【C18】______with angry responses insisting there are other ways low-energy radiation can【C19】______. "I don’t like cell phones and I don’t like writing about cell phones," says Park, "【C20】______the damned issue just won’t go away. "
【C20】
选项 A、but
B、besides
C、hence
D、meanwhile
答案A
解析 逻辑关系题。此处表示转折关系。besides表示递进关系；hence(因此)表示因果关系；meanwhile(同时)表示并立关系。
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