wide renewed traditional resources alternative widely exhaust power all the There is now increasing concern about the world's energy (1) particularly about those involving fossil fuels. In less than a hundred years, we shall probably (2) present sources of oil and gas. The world's coal reserves should last longer but, once used, these cannot be (3) It is important, therefore, that we should develop such (4) sources of energy as solar energy as well as water and wind (5) classed as renewable energy. Until these energy supplies are (6) used, it is important for developed countries to reduce energy consumption as much as possible.