问题补充：
Since the first Earth Day started on April 22, 1970, people around the world have been encouraged to protect the environment and natural resources．Gaylord Nelson started this holiday．On the first Earth Day， 20 million people took part in Earth Day events．
Earth Day activities can include learning something about technology like cars that are more environmentally friendly and special houses that save energy and water．An organization called the Earth Day Network encourages people to use clean energy which doesn’t pollute the environment．Most of our energy comes from fossil fuels (化石燃料) that are found underground． Coal， oil and natural gas are examples of fossil fuels．Fossil fuels come from plants and animals that lived millions of years ago． Burning fossil fuels to create energy pollutes the air and water． Many scientists think that burning fossil fuels also increases the temperature of the earth． To reduce the use of fossil fuels． scientists are experimenting with hydrogen-powered (氢化发动的) cars． These cars don’t pollute the air like gas-powered cars．
Some scientists guess that by 2025, fossil fuels will run out．When people can no longer use gasoline， they may use fuel cells instead． Fuel cells use hydrogen to create energy． People do not need to worry about hydrogen running out， because it is renewable and replaceable．
In Washington， D.C.， a few people drive cars that run on fuel cells． When these cars need more energy, drivers can go to a hydrogen pump．The first hydrogen pump for the public opened in November ， marking an important step toward a cleaner environment．
【小题1】what can we learn from the passage?
A．Fossil fuels don’t pollute the air．
B．Hydrogen-powered cars make less pollution．
C．Many drivers are driving hydrogen-powered cars．
D．We can find many hydrogen pumps in the USA．
【小题2】How long may people still be able to use fossil fuels?A．Twenty years．B．Over thirty-eight years．C．More than ten years．D．About seventeen years．【小题3】Which of the following is not mentioned?A．Scientists are producing more hydrogen-powered cars．B．Some people drive fuel-cell cars in Washington．C．Fossil fuels come from plants and animals．D．We can learn about environmentally friendly technology from Earth Day activities．【小题4】When do fossil fuels pollute the air?A．When we use them to create gasoline． B．When people get them from the underground．C．After being burned to get energy．D．After getting them from a hydrogen pump．【小题5】Because hydrogen is renewable， we don’t need to worry that ．A．it will be used upB．it can be used for creating energyC．it will pollute the environmentD．it will be cleanerB
答案：
(答案→)B
解析：这篇短文主要介绍了自第一个地球日以来世界各地的人们已经被鼓励保护环境和自然资源。在第一个地球日,2000万人参与活动。为了减少污染，在华盛顿有人开始开燃料电池的汽车。
【小题1】细节理解题。根据短文第二段scientists are experimenting with hydrogen-powered (氢化发动的) cars． These cars don’t pollute the air like gas-powered cars描述，氢化发动的汽车不像油发动的汽车一样污染空气，故选B。
【小题2】推理判断题。根据第三段科学家的推测可知，到2025年化石燃料将耗尽，人们将利用氢制造能量的燃料电池，故大约还能使用化石燃料十年。故选C。
【小题3】细节理解题。根据短文描述，可知A项没有在文章中提及，
【小题4】细节理解题。根据第二段Burning fossil fuels to create energy pollutes the air and water描述燃烧化石燃料创造能量时会污染空气和水。故选C
【小题5】细节理解题。根据第三段People do not need to worry about hydrogen running out， because it is renewable and replaceable描述人们不必担心氢耗尽，因为它是可再生的和可替换的。
