photovoltaic cells that convert sunlight to electricity. In the US alone, more than 100,000 homes are equipped with solar electric systems in the form of solar panels or solar roof tiles.And in other parts of the world. including many developing countries the use of solar system is growing steadily. Another alternative energy source which is abundant in specific geographical areas, is geothermal power, which creates energy by tapping beat from below the surface of the earth. Hot water and steam that are trapped in underground pools are pumped to the surface and used to run a generator, which is produces electricity. Geothermal energy is 50,000 times more abundant than the entire known supply of fossil fuel resources. And as with solar power the technology needed to utilize geothermal energy is fairly simple. A prime example of effective geothermal use is in Iceland, a region of high goothermal activity where over 80 percent of private homes are heated by geothermal power. Solar and geothermal energy are just two of promising renewable alternatives to conventional energy sources. The time is long overdue to invest in the development and use of alternative energy on global scale. Question 31. What is the main topic of this passage? A. The benefits of solar and wind power over conventional energy sources. B. How energy resources are tapped from nature. C. Two types of alternative energy sources that should be further utilized. D. Examples of the use of energy sources worldwide. Question 32. According to the passage, why should we consider using alternative energy sources? A. Because fossil fuels are no longer available. B. Because global warming has increased the amount of sunlight that reaches the earth. C. Because they are free and available worldwide. D. Because conventional energy resources are being depleted,and they cause environmental damage. Question 33. Which of the following words could best replace the word "harnessing"? A. Capturing B. Harassing C. Depleting Question 34. According to the passage, what can be inferred about solar roof tiles? A. They are being used in many undeveloped countries. D. Exporting B. They can convert geothermal energy to electricity, C. They are more expensive than solar panels. D. They contain photovoltaic cells. Question 35. According to the passage, how is solar energy production similar to geothermal energy production? A. They both require the use of a generator. B. They both use heat from the earth's surface. C. They both require fairly simple technology. D. They are both conventional and costly. Question 36. Where is the best place in the passage to insert the following sentence: "Although the US is not utilizing geothermal resources to this extent, the Western US has a similar capacity to generate geothermal power"? A. after the phrase "earth-friendly" C. after the phrase"by geothermal power" B. after the phrase "growing steadily" D. after the phrase "global scale" Question 37. According to the passage, which of the following is true about solar power? A. There is very little of it available in Iceland. B. It is being used in 100,000 private homes worldwide. C. It is 6,000 times more powerful than energy from fossil fuels. D. There is enough of it to far exceed the energy needs of the world. Question 38, What can be inferred about the use of geothermal energy in Iceland? A. It is widely used form of energy for heating homes. B. Twenty percent of the geothermal energy created is used to heat businesses. C. It is not effective for use in private homes. D. It is 80 times more effective than traditional forms of energy. Question 39. What does the author imply about alternative energy sources? A. Many different types of alternative energy sources exist. B. Most alternative energy sources are too impractical for private use. C. Alternative energy is too expensive for developing countries to produce D. Solar and geothermal energy are the effective forms of alternative Question 40. What best describes the author's purpose in writing the passage? A. To warn people about the hazards of fossil fuel use.