5．Scientists have helped people understand the dangers facing the earth．As people live on the earth，we should be fully ready to deal with the dangers．If we do not pay more attention to the problems caused by air pollution，our earth may no longer be a healthy place for plants，animals，and people to live．
Cleaning up the air is a job that all countries must work on．The problems caused by air pollution can be solved，but a lot of work needs to be done．Governments around the world are beginning to work together to lower the levels of dangerous gases in the atmosphere（大气层）．If this can be done well，the ozone layer（臭氧层） can rebuild itself，global warming can be controlled，and acid rain can be reduced．
In 1967，the government of the United States passed the Clean Air Act．More parts were added to the act in 1970，1977and 1990．As a result of these laws，cars now must reduce the amounts of harmful gases．Power factories must use"clean coal"methods to reduce acid-rain gases they produce．
In 1970，the Environmental Protection Agency （EPA） was set up．The EPA's job is to make sure that the environmental laws are being followed and to find out new dangers and offer solutions．The first Earth Day was also celebrated in 1970．
While it is very important to address with air on a global scale，each person can also do something to protect the Earth．Here are some things you can do every day：
1）Turn down the heat and air conditioning．
2）Use the dishwasher only when they are full of dishes．
3）Practice the 3Rs：recycle，reuse，and reduce．
4）Plant a tree．
5）Walk or ride your bike．
76．If we don't care aboutA problems，our earth may no longer be a healthy place．
A．Air pollution
B．Water pollution
C．Noise pollution
77．Every country shouldB to solve the problems caused by air pollution．
A．rebuild the ozone layer
B．clean up the air
C．produce harmful gases
78．All the things the EPA can do is toC
A．make more laws
B．find out new dangers
C．protect the environment
79．The Clean Air Act was passedA by the American government．
A．In 1967
B．In 1970
C．In 1977
80．In our daily life，we can do something to protect the earth byB．
A．using more cars
B．riding the bikes
C．cutting down trees．
分析 如果我们不更多的关注大气污染，地球将可能不再是人类，植物和动物可以生存的健康的地方了，政府将会一起努力降低大气层里面的危险气体，这样能帮助重建臭氧层，控制全球变暖，在日常生活中我们也可以做些事情去保护我们的地球．
解答 ABCAB
76．A．细节题，结合第一段If we do not pay more attention to the problems caused by air pollution，our earth may no longer be a healthy place for plants，animals，and people to live．如果我们不更多的关注大气污染，地球将可能不再是人类，植物和动物可以生存的健康的地方了，故选A．
77．B．细节题，结合第二段Cleaning up the air is a job that all countries must work on．可知清理大气是所以国家都应该做的事情，故选B．
78．C．推理题．结合第四段The EPA's job is to make sure that the environmental laws are being followed and to find out new dangers and offer solutions是要确保环境法被实施，发现新的危险提供解决办法，可知目的都是为了保护环境，故选C．
79．A．细节题，根据第三段In 1967，the government of the United States passed the Clean Air Act可知是1967年，故选A．
80．B．细节题，结合最后Walk or ride your bike．可知我们可以走路或者骑自行车去保护环境，故选B．
点评 阅读题型，要注重句子与句子之间、段落与段落之间逻辑关系以及对篇章的整体理解．根据所给问题选择正确选项完成试题．
