单项选择题

Nuclear energy is an efficient and convenient substitute for conventiona l forms of energy which were found in special geographical locations. Large amounts of 61 and effort are required to 62 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 63 places. This increases the difficulties of 64 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 65 of nature in order to obtain the energy. For equal amounts of energy, nuclear energy is much more convenient and inexpensive to obtain than conventiona l sources of energy. With nuclear energy, the amount of pollution is greatly reduced. 66 the production of nuclear energy is based on the fission of atoms, pollution is kept to a very low level. The energy produced in the reactors in converted into heat and electricity, and these have 67 or no pollution at all. Conventional forms of fuel, 68 , produce large amounts of pollution. Production of nuclear energy uses the 69 of the fission of atoms; thus, 70 amounts of energy can be obtained from it. The world’s reserves of oil, coal and natural gas are running 71 at a tremendous rate and current estimates predict that 72 of the 21st century, most of these conventional fuels will be used up. Nuclear energy is the exception 73 this gloomy prediction. Through splitting and fusing atoms, large amounts of energy can be produced, and 74 this process can go on an don until all our energy needs are satisfied. The 75 of nuclear energy as a boundless source of energy is indeed great, and we must harness it whenever possible as conventiona l fuels will not be around much longer.

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