Nuclear power’s danger to health, safety, and even life itself can be summed up in one word: radiation. Nuclear radiation ha

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问题     Nuclear power’s danger to health, safety, and even life itself can be summed up in one word: radiation.
    Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can’t be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can’t sense radioactivity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things.
    At very high levels, radiation can kill an animal or human being outright by killing masses of cell in vital organs. But even the lowest levels can do serious damage. There is no level of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be significant. This is the case when only a few cells are hit, and if they are killed outright. Your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They reproduce themselves in a deformed way. They can grow into cancer. Sometimes this does not show up for many years.
    There is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can be irradiated and feel fine, then die of cancer five, ten, or twenty years later as a result. Or a child can be born weak or liable to serious illness as a result of radiation absorbed by its grandparents.
    Radiation can hurt us. We must know the truth.
The word "significant" in Paragraph 3 most probably means______.

选项 A、remarkable
B、meaningful
C、fatal
D、harmful

答案C

解析 本题是一道词汇含义类问题。问第三段中的词significant是什么意思。该词在文章第三段第四句中。上下文意为,任何强度的辐射都不安全。如果辐射击中少量细胞并立刻杀死这些细胞,就不会危及生命,因为这些死亡的细胞会被健康的细胞代替。如果辐射只是损伤了细胞,反而会产生致命后果,引起癌症。因此,本题的正确答案应是C“致命的”。从上下文分析,这里significant不应该仅指“有害的”(harmful),应指“致命的”。
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