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.
Radiation can cause serious consequences even at the lowest level______.

选项 A、when it kills few cells
B、if it damages few cells
C、though the damaged cells can repair themselves
D、unless the damaged cells can reproduce themselves

答案B

解析 本题问即使是少量的核辐射也可以在什么情况下导致严重的后果。第三段指出,即使少量的辐射也会引起严重的伤害,任何强度的辐射都不是安全的。如果辐射不损伤重要器官,就不会危及生命。例如,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,因为死亡的细胞会被健康的细胞代替。但是,如果这些细胞只是受到损伤,而受损的细胞又不断繁殖的话,就危险了,因为,如果这些畸形细胞繁殖,就会转化为癌。这一过程有时需要多年才显现出结果。因此,本题的正确答案应是B“要是它损伤为数不多的细胞的话”。
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