Questions 76 to 80 are based on the following passage:
　　Any talk of the energy needs of the United States should include adiscussion of the Tennessee Valley Authority, a successful but sometimesquiet federal agency. The Tennessee valley Authority began life in 1933 asone of the public works agencies designed to help fight the Great Depression.The TVA was first meant to employ thousands of men to build a chain of damsdown the Tennessee River. These dams were to include electric plants forgenerating electricity to provide cheap power for the rural land in thevalley area.
　　Within ten years, most of the homes in the TVA area had electricity. Intwenty years, there were four times as many homes in the area with power.At first , TVA electrcity cost a penny per kilowatt. Many homes in the arearelied on electricity for heating. This results in criticism now that elec-tricity is more than three pennies per kilowatt. Other criticism has beenaimed at the TVA's other methods of generating power in 1975. The Authoritywas sued(?e??) for polluting the air with its coal-generating plants. Anti-nuclear groups point out that the TVA would soon have a total of seventeenatomic reactor plants supplying power for its service area. But the TennesseeValley Authority has adjusted to the new times. It quickly became a modelfor pollution control at its coal plants. Just as quickly the TVA founditself an energy conserver as well as a producer. The TVA conducts freehome energy consultations and offers cheap loans to consumers who want toinstall insulation storm windows, solar energy equipment or woodburningstoves. The resulting decrease in demand has allowed the TVA to postponeor delay construction of two nuclear reactors. Instead, the Authority isbuilding a plant to extract coal gas from low-grade coal. Their first stepwill be to use the coal gas to make an ammonia(???à) fertilizer for farmersin the TVA service area. Their ultimate goal is to produce a syntheticfuel from the coal gas. The TVA will then be once again producing a cheapersource of energy and helping solve the nation's problems, several at atime.
　　76. The main idea of this passage is that ____________.
　　A) electricity purchased by TVA's customers has tripled in price.
　　B) the TVA has not served its function well.
　　C) the TVA is dangerous to the environment.
　　D) the TVA has always been a pioneer in the energy field.
　　77. According to the passage, which of the following statements is NOT true?
　　A) The Tennessee Valley Authority was created in 1933.
　　B) The TVA's initial function was to provide work for the unemployed.
　　C) The TVA has been making an effort in decreasing the number of nuclear reactor plants it depends on.
　　D) The TVA is interested in producing coal gas from low-grade coal.
　　78. We can conclude from the passage that ____________.
　　A) the TVA no longer supplies electricity for heating
　　B) before the time of the TVA, few homes in the Tennessee valley had electricity
　　C) the TVA has not had to rely on atomic reactor for its power
　　D) coal gas is expensive to produce采集者退散
　　79. The passage suggests that ____________.
　　A) the TVA is now privately owned
　　B) the TVA is more interested in what is good for the nation than in making money
　　C) synthetic fule is cheaper to produce than electricity
　　D) ammonia fertilizers are nonpolluting
　　80. As used in this passage, the word "extract" means ____________.
　　A) burn B) reshape
　　C) defy D) remove from