The discussion on renewable energy has been going on for at least a decade and people have relied on fossil fuels almost entirely for more than a century.However，the situation when fossil fuels were the most efficient and the cheapest source of energy has been left far in the past.Many countries such as Germany and Sweden have already made significant efforts to fix this situation，employing numerous power plants working on the renewable resources of energy.The most effective among these resources is geothermal(地热的) energy.
Geothermal energy does not depend on the world’s economic and political situation as strongly as fossil fuels do. Besides, extracting(提炼) fossil fuels adds up to the price of energy produced from them.Therefore，geothermal energy is much cheaper than traditional ones，saving up to 80% of the costs over fossil fuels.
Being a renewable resource，geothermal energy produces less waste and pollution than traditional energy sources.In geothermal systems，carbon dioxide makes up about 10% of air produced.Overall，in order to produce the electricity that can be used for one hour，the geothermal systems produce 0.1 pound of carbon dioxide and other harmful gases.For a comparison，a power plant producing electricity from gas produces up to 2 pounds of carbon dioxide into the atmosphere，and those power plants that work on coal(煤) produce an astonishing 3.6 pounds of greenhouse gases.
Low costs make another reason why using geothermal power plants should be the first choice for many countries.Geothermal heat systems require 25% to 50% less energy for work compared with the traditional systems for heating or cooling.Besides，geothermal equipment is less bulky：due to the very nature of geothermal energy，geothermal power plants have only a few moving parts，all of which can be easily sheltered inside a relatively small building.What’s more，the life span of geothermal equipment is rather long.All these make geothermal power stations easy to build and keep.
【解题导语】 地热作为非常重要的可再生清洁能源，将会给人们带来巨大的好处。
1．Fossil fuels are more expensive than geothermal energy partly because________．
A．fossil fuels are nearly used up
B．it is free to use geothermal energy
C．the production of fossil fuels costs a lot
D．geothermal energy doesn’t depend on political situation
C 解析：细节理解题。根据第二段第二句Besides，extracting(提炼) fossil fuels adds up to the price of energy produced from them.可知，化石燃料需要经过提炼才能生产出来，所以这大大增加了它的生产成本，故答案为C项。
2．According to Paragraph 3，what can be concluded from the comparison?
A．Coal is much more efficient than gas.
B．Geothermal energy is environmentally friendly.
C．Gas and coal are often used to produce electricity.
D．The geothermal systems don’t produce harmful gases.
B 解析：推理判断题。根据第三段后两句可知，经过对比发现，用地热能源生产电比用汽油和煤炭生产电更环保，因为用地热能源生产电排放的温室气体较少，故答案为B项。
3．What does the underlined word“bulky”in the last paragraph mean?
A．Being really big and heavy.
B．Being convenient to operate.
C．Being expensive and low effective.
D．Being unfriendly to the environment.
A 解析：词意猜测题。根据最后一段第三句中的due to the very nature of geothermal energy，geothermal power plants have only a few moving parts，all of which can be easily sheltered inside a relatively small building可知生产地热的设备不是那么大而笨重的，因为它只有一些运转部件并能够放在相对小的建筑中，故答案为A项。
4．What is the main idea of this passage?
A．Fossil fuels are being run out of.
B．Geothermal energy is well accepted.
C．Geothermal energy has many advantages.
D．Many countries have benefited from geothermal energy.
C 解析：主旨大意题。作者主要通过价格、环保、运行成本这三方面证明了地热能源比传统能源更有优势，故答案为C项。
