【案例分析题】

There are three separate sources of hazard【C1】______to the use of nuclear reaction to supply us with energy.Firstly，the radioactive material must travel from its place of manufacture to the power station【C2】______the power stations themselves are solidly built，the container used for transport of the material are not.Unfortunately ，there are【C3】______only two methods of transport available，【C4】______road or rail，and both of these【C5】______close contact with the general public，【C6】______the routes are【C7】______to pass near，or even through，【C8】______populated areas.Secondly，there is a problem of wastes.All nuclear power stations produce wastes which【C9】______will remain radioactive for thousands of years.It is【C10】______to deactive these wastes，and so they must be stored【C11】______one of the ingenious but cumbersome ways that scientists have invented.For example，they must be buried under the ground【C12】______sunk in the sea.However，these【C13】______do not solve the problem completely，they merely store it，since an earth-quake could【C14】______open the containers like nuts.Thirdly，there is the problem of accidental exposure【C15】______to a leak or an explosion atthe power station.【C16】______with the other two hazards，this is not very likely and does not provide a serious【C17】______to the nuclear program，【C18】______it call happen，as the inhabitants of Harrisburg will tell you.Separately，and during short periods，these three types of risk are no great cause for concern.【C19】______，though，and especially【C20】______much longer periods，the probability of a disaster is extremely high.

【C1】（）