Question

  The earth is about 4. 6 billion years old. We humans 1      (live) on the earth for a long time,and we have changed our planet a lot in many ways. Some things we've done are very good for the earth 2        some are bad.

  Fewer trees All over the world,people have cut down 3       (million) of trees. When it rains or when the wind blows,the earth 4       (take) away. Forests have become deserts. So more and more sorts of animals and plants are disappearing.

  Traffic and factory pollution In big cities,cars and buses have polluted the air. Now many people in cities have health problems. Factories have also polluted the land and the water. As a 5       ,many rivers and lakes are now dead.

  The ozone layer (臭氧層) Around the earth,there's a special kind of oxygen (O₂) 6       (call) "ozone" (O₃) . It's important to the earth. But now air pollution is destroying it and that has made a very big hole in the ozone layer. Too much harmful radiation (輻射) from the sun passes 7        the hole and reaches the earth directly. This is very dangerous because this kind of radiation 8        cause cancer.

  More carbon dioxide (C0₂) Carbon dioxide in the air has increased a lot. It 9       (main) comes from burning oil,coal and wood. This has formed a "blanket" around the earth. The heat from the sun can't escape so the temperature is rising. That is called "the greenhouse effect (溫室效應) ". 10       causes the level of the oceans to rise and the climate (氣候) of the earth to change.

All these problems are very serious,so we must do something now.

1.        2.        3.        4.        5.         

6.        7.        8.        9.        10.       

Answer 1

1. have lived考查時態。人類在地球上已經生存了很長時間。

2. while考查連詞。while在此處表示對比，可譯為"而"。

3. millions考查數同。million表示不確切的數字時用復數且和of連用。

4. is taken考查被動語態。句意：下雨或刮風時，泥土被帶走。

5. result考查固定短語。as a result意為"結果"。

6. called過去分詞作后置定語，表示被動意義，表示"被稱為"。

7. through 考查介詞。從內部穿過用through。

8. can考查情態動詞。句意:這很危險因為這種輻射會導致癌癥。

9. mainly考查副詞。mainly修飾動詞come。

10. It考查代詞。it在此處代替"溫室效應"。