Nuclear energy is an efficient and convenient substitute for conventional forms of energy which were found in special geographical locations. Large amounts of 【B1】______ and effort are required to 【B2】______ 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 【B3】______ places. This increases the difficulties of 【B4】______ 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 【B5】______ 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. 【B6】______ 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 【B7】______ or no pollution at all. Conventional forms of fuel, 【B8】______ , produce large amounts of pollution. Production of nuclear energy uses the 【B9】______ of the fission of atoms; thus, 【B10】______ amounts of energy can be obtained from it. The world's reserves of oil, coal and natural gas are running 【B11】______ at a tremendous rate and current estimates predict that 【B12】______ of the 21st century, most of these conventional fuels will be used up. Nuclear energy is the exception 【B13】______ this gloomy prediction. Through splitting and fusing atoms, large amounts of energy can be produced, and 【B14】______ this process can go on and on until all our energy needs are satisfied. The 【B15】______ 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. 【B1】______