题目内容：
根据以下材料，回答题Nuclear Energy
Nuclear energy is an efficient and convenient substitute for conventional forms of energy which were found in special geographical locations. Large amounts of __________ (51) and effort are required to __________ (52) these locations. Once the sites are found, men and equipment must be brought to tap and use these sources of energy. However, a large proportion of such sites are found only in far and __________ (53) places. This increases the difficulties of __________ (54) these forms of energy. With nuclear energy, such difficulties are not present. Nuclear reactors can easily be built anywhere, and man does not have to compete with the __________ (55) of nature in order to obtain the energy. For equal amounts of energy, nuclear energy is much more convenient and inexpensive to obtain than conventional sources of energy.
With nuclear energy, the amount of pollution is greatly reduced. __________ (56) the production of nuclear energy is based on the fission (裂变) of atoms, pollution is kept to a very low level. The energy produced in the reactors is converted into heat and electricity, and these have __________ (57) or no pollution at all. Conventional forms of fuel, __________ (58), produce large amounts of pollution.
Production of nuclear energy uses the __________ (59) of the fission of atoms; thus,__________ (60) amounts of energy can be obtained from it. The world's reserves of oil, coal and natural gas are running __________ (61) at a tremendous rate and current estimates predict that __________ (62) of the 21 st century, most of these conventional fuels will be used up. Nuclear energy is the exception __________ (63) this gloomy prediction. Through splitting and fusing atoms, large amounts of energy can be produced, and __________ (64) this process can go on and on until all our energy needs are satisfied. The __________ (65) of nuclear energy as boundless source of energy is indeed great, and we must harness it whenever possible as conventional fuels will not be around much longer.
回答(51)题 A．capital
B．incentive
C．interest
D．currency
参考答案：
答案解析：