七、按要求改写句子。
1. You shouldn't drive too much.(改为祈使句)
too much.
2. Workers can use wood to make chairs.(同义句转换)
Workers can chairs wood.
3. We should save energy because it is useful.(对画线部分提问)
we save energy?
4. The man put the picture on the wall.(改为否定句)
The man the picture on the wall.
5. keep，you，your，the，sweep，room，floor，clean，to，can(.)(连词成句)

1. Don't; drive
2. make; with
3. Why; should
4. didn't; put
5. You can sweep the floor to keep your room clean.

1. 祈使句的否定形式结构为“Don't + 动词原形”，将原句的shouldn't转换为该结构即可。
2. “use sth to make sth”的同义表达为“make sth with sth”，意为“用某物制作某物”。
3. 对原因状语提问用疑问词Why，原句包含情态动词should，疑问句结构为“Why + should + 主语 + 动词原形”。
4. 原句是一般过去时，谓语为实义动词put，变否定句需借助助动词didn't，后面跟动词原形put。
5. 确定主语you，情态动词can，谓语sweep the floor，再结合目的状语to keep your room clean，组合成通顺的句子。

八、从方框中选择合适的句子补全对话。(其中有一项是多余的)

A：What are you doing，Bill?
B：1.
A：2.
B：It's about trees. What do you know about trees?
A：Trees are important to us. We can get fruit from trees. 3.
B：Good. Then what do we use wood for?
A：4. It's very useful.
B：But people cut down too many trees to get wood every year. The Earth gets sick now.
A：5.
B：We should stop cutting down so many trees，and we should plant more trees.
A. We use wood to make pencils，desks，chairs and paper.
B. What is it about?
C. What should we do to keep our school clean?
D. I'm reading a book.
E. What should we do to help the Earth?
F. We can get wood from trees too.

1. D
2. B
3. F
4. A
5. E

1. 上文A询问Bill正在做什么，需回答正在进行的动作，对应选项D。
2. 下文B回答内容是关于树的，所以上文应询问相关内容的主题，对应选项B。
3. 前文提到可以从树上获取水果，结合后文对木材用途的讨论，此处补充说明还能从树上获取木材，对应选项F。
4. 上文B询问木材的用途，此处需回答木材的具体用途，对应选项A。
5. 前文提到地球因树木被过度砍伐出现问题，下文B给出了保护地球的做法，所以此处应询问帮助地球的方法，对应选项E。