Coal, oil, and natural gas supply modern civilization (nền văn minh) with most of its power. However, not only are supplies of these fuels limited, but they are a major source of pollution. Therefore, it's important to improve, explore and develop such alternative energy sources as nuclear, water, solar and wind power. Each of these alternatives, however, has advantages and disadvantages. Nuclear power plants efficiently produce large amounts of electricity without polluting the atmosphere; however, they are costly to build and maintain, and they create the difficult problem of what to do with nuclear waste. Hydroelectric (thủy điện) power is inexpensive and environmentally safe, but impractical for communities located far from moving water. Wind power is a pollution-free source of renewable energy but it cannot be used in many parts of the world where there is insufficient wind. Solar power is renewable. it does not cause pollution and it does not add the earth's heat load. However, it is difficult to collect and store. Solar power also requires expensive equipment. 1. Coal, oil, and natural gas __________ A. are very great in amount B. will never be used up C. pollute the atmosphere D. supply most of its power 2. Nuclear power plants _____________ A. are difficult to build B. pollute the atmosphere C. are very cheap to maintain D. create the problem of nuclear waste 3. Wind power plants _________ A. cannot be used in places that has strong wind B. is never completely used up C. is a source of pollution D. cannot replace itself 4. What is the advantage of these alternatives? A. They are environmentally friendly energy sources B. They are non-renewable forms of energy C. They are all very practical D. They are inexpensive to exploit