A.Compare B.When comparing

C.Comparing D.When compared

提示：compare与the biggest ocean 之间存在动宾关系，故用过去分词作状语。

答案：D

4.1)完成句子

(1)这个老人已独自生活四十年了。

The old man has lived __________for 40 years.

(2)我和哥哥有各自的房间。

My brother and I have __________ __________.

(3)久别重逢，朋友们非常高兴。

The friends were glad to meet after__________ __________ __________.

(4)她父母分居但没离婚。

Her parents are__________but not divorced.

答案：(1)separately　(2)separate rooms　(3)a long separation　(4)separated

2)单项填空

They got__________in the crowd.

A.divided B.apart C.separated D.cut

提示：get separated指"被......分开了"。

答案：C

3)用separate与divide 的适当形式填空

(1) __________your things from mine.

(2)This house is__________into parts.

(3)The police tried to __________the two men who are fighting.

(4) __________the cake into 3 equal pieces.

答案：(1)Separate　(2)divided　(3)separate　(4)Divide

5.1)单项填空

A good dictionary is a(an)__________on the meanings of words.

A.right B.authority C.way D.author

提示：句意为"一本好的词典是词义方面的权威"。authority"权威"；right"权利；对比";way"方法；手段；方式",author"作家"。

答案：B

2)完成句子

(1)我们是经联合国授权行动的。

We acted__________ __________ __________ __________the UN.

(2)我得向官方报告此事。

I have to report this___________ _________ __________.

(3)现在谁掌权?

Who is__________ __________now ?

答案：(1)under the authority of 　(2)to the authority　(3)in authority

6.单项填空

Iron__________when it's heated.

A.extends B.spreads C.widens D.expands

提示：句意为"铁受热膨胀"。expand 指"由于内部或外部的力量而使物体扩大"；extend指"时间与空间的延伸"；spread 指"传播"；widen"加宽"。