B．the plants multiplied and filled the oceans with oxygen

C．plants played an important part in the appearance of the animals

III.句型背诵

1.The earth became so violent that it was not clear whether the shape would last or not.

地球(开始)变得激烈动荡，不知道这个固体形状是否会继续存在下去。

2.What is even more important is that as the earth cooled down，water began to appear on its surface.

更为重要的是当地球平静下来时，水开始在地球表面出现了。

3．This produced a chain reaction，which made it possible for life to develop.

这就产生了一种连锁反应，使得生命的发展成为可能。

4．So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.

所以，在未来的数百万年中，生命能否在地球上延续取决于这个问题能否得到解决。

达标练习

I.用方框内所给短语的适当形式填空

in time； lay eggs； give birth to； in one's turn； prevent...from；

be fundamental to block out cheer up now that be harmful to 1．A bird ____________in the nest it has built.

2．Luckily, we arrived at the station______________.

3．No matter what will happen，nothing and nobody can ____________the plan ________being carried out.

4．Smoking too much _______________ your health.

5．After the second competitor went off the stage，my son went onto the stage to perform_______________.

6．He told us happily that his wife would _________________ a baby the next week and that he would be a father.

7．We put a curtain across the window to the sunlight.

8．You ought to have a good rest you've finished the work.

9．I do hope she can and accept the challenge of life bravely!

10.The sun to plants.