Introduction Although the world is large, man is able to live in only a small part of it. The atmosphere is only about eleven kilometers thick. The soil that supplies us with food is only about fifteen centimeters thick and man can live on only about one eighth of the world's surface. In the past two hundred years man has greatly changed his environment. Water has been given to deserts. Roads have been built across deserts and through forests
Go back to sth. Return to an earlier point in space or time How far does your memory go back? 让我们回到原来正在讨论的问题上去吧 Let's go back to the subject we were discussing? ·若要探讨爱尔兰问题的起源我们得回到几百年前. To trace the origins of the Irish problem, we have to go back over three hundred years
Pre-reading Questions 1. Name several pollutants 2. Who causes pollution? 3. Why is pollution one of the most serious problems that man faces these days? 4. Why is the pollution problem complicated? 7. 5. How can pollution be gradually reduced? 6. When did man begin to pollute his
1. In what physical condition is the writer's grandmother? with her? 3. Is she happy Why or why not? 4 Are retirement homes all bad? 5. What did the writer's mother decide to do when Grandma could not live on her own? 6. How are elderly people treated in many cultures? 7. Why are old people unhappy in a nursing home? 8. What is the writer's opinion concerning the treatment of aging people? 9. What is your own opinion concerning the old people n general?
