Nuclear radiationhas a certain mystery, partly because it cannot be detected by

Nuclear radiation（核辐射）has a certain mystery,partly because it cannot be detected（探测） 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. Forexample, radio waves are all around but we can’t detect them or sense themwithout a radio receiver. Similarly, we can’t sense radioactivity without aradiation detector. But unlike common radio waves, nuclear radiation is notharmless to human beings and other living things.

At very high levels, radiation can kill ananimal or human being outright by killing masses of cells in important organs.Even the lowest levels can do serious damage. There is no level of radiationthat is completely safe. If the radiation does not hit anything important, thedamage may not be serious. This is the case when only a few cells are hit, andwhen they are killed outright. Your body will replace the dead cells withhealthy ones. But if the few cells are only damaged, and if they reproducethemselves, you may be in trouble. They reproduce themselves in an unusual way.They can grow into cancer. Sometimes this does not show up for many years.

This is another reason for some of themystery about nuclear radiation. Serious damage can be done without theknowledge of the person at the time that damage has occurred. A person can beirradiated（放射治疗）andfeel fine, then die of cancer five, ten, or twenty years later as a result. Achild can be born weak or easy to get serious illness as a result of radiationabsorbed by its grandparents.

1.According to the passage, the danger ofnuclear power lies in __________.

2.Radiation can lead to serious troubleeven at the lowest level __________.

3.Radiation can hurt us so much that it can___________.

4.Which of the following can be bestinferred from the passage?

5.What would be the best title of the text?

试题答案

【答案】

1.D

2.B

3.D

4.A

5.A

【解析】

试题