are surprise of the and natural gas with most of its power. However, not only supply modern civilization with mystoris power. However, not only are supplies of these fuels major source of pollution If the energy demands of the be improved or further explored and developed These include nuclear, water, solar wind,and goothermas advantages and disadvantages. geothermal power.as well as energy from new, nonpolluting types of fuels. Each of these alternatives, Nuclear power plants produce large amounts of electricity without polluting the atmosphere with nucleur wastes Hydroelectric power is inexpensive and environmentally safe, but atmosphere however, they are costly to build and maintain and they pose the daunting problem of impractical for communities located far from moving water energy from tides and waves drawbacks. Solar power holds great promise for the future but methods of collecting and concentrating sunlight are as yet inefficient, as are methods of harnessing wind power. Every source of energy has its disadvantages. One way to minimize them is to use less energy. Conservation efforts coupled with renewable energy resources, such as a combination of solar water, wind, and geothermal energy and alternative fuels, such as alcohol and hydrogen,will ensure supplies of clean, affordable energy for humanity's future. 71. The passage mainly discusses __ . A. the current situation of energy demands B. the way to use less energy. C. the difficulties in finding new sources of energy. D. the advantages and disadvantages of some sources of energy. 72. The word "dwindling "in paragraph 1 is closest in meaning to " __ 1) A. rocketing B. declining C. doubling D. distributing 73. According to the passage, which of the followin;; is the limitation of natural gas? A. It is difficult to be collected. C. It is polluted. B. It is expensive. D. It is inaccessible for people who live far away the cities. 74. What does the word "its" in paragraph 2 refer to? A) modern civilization B oil C. natural gas D. coal 75. The word "drawbacks " in paragraph 3 is closest in meaning to " __ C. disabilities A. objections B. methods 76. According to the passage which of the following is NOT true? D. problems A. Just like coal nuclear energy is a pollutant to the air. B. It is hard for people away from the water to use hydroelectric power. C. Scientists are on their way to look for alternative sources of energy. D. Wind power and solar power have the same problem. 77. What can be inferred from the passage? A. Scientists will not resume their search for new types of energy until they have found a perfect one. B. Using hydroelectric energy can be harmful to our atmosphere. C. It is impossible for some groups of people to enjoy water energy. D. The only way to decrease the disadvantages of sources of energy is to use them less. 78. What does the word "they" in paragraph 3 refer to? A nuclear power plants. C. advantages and disadvantages. B. amounts of electricity. 79. What can be inferred about wind power? D. nuclear wastes. A. Combining it and solar energy can ensure humanity's future energy demands B. People living away from rivers and oceans cannot benefit it. C. It is promising but very expensive. D. An effective way to hamess wind power has not been figured out. 80. The author of this passage is trying to __ A. support scientists in their search for new sources of energy. B. present some new sources of D. explain the benefits and shortcomings of some kinds of energy. D. calculate the energy demands of the future.