Many people still believe that natural resources will never be used up. Actually, the world’s energy resources are limited. Nobody knows exactly how much fuel is left. However, we also should use them economically and try to find out alternative sources of power. According to Professor Marvin Burnham of the New England Institute of Technology, we have to start conserving coal, oil and gas before it is too late; and nuclear power is the only alternative. However, many people do not approve of using nuclear power because it’s very dangerous. What would happen if there was a serious nuclear accident? Radioactivity causes cancer and may badly affect the future generations. The most effective thing is that we should use natural resources as economical as possible. 29. Many people still believe that natural resources will never be ________. A. reduce B. rised C. run out of D. raised 30. According to the writer , we should use energy resources ________. A. economically B. regularly C. financial D. less 31.The word “ approve” in the passage is closet in meaning to ____________. A. disagree B. agree C. improve D. explain 32. ___________ causes cancer and may badly affect the future generations. A. Coal B. Fuel C. Radioactivity D. Electricity 33. Which of the following is NOT true about nuclear power? A. unsafe B. safe C. risky D. dangerous