句型50：... so that ...

　　Put the tree in the hole so that it is straight. 把树放入洞穴中，让它立直。

　　句型51：be＋num. ＋metres / kilometres / years...＋long / wide / deep / high / old...

　　The Great Green Wall is 7，000 kilometres long. 绿色长城长7000公里。

　　The river is about 2 metres deep. 这条河大约有2米深。

　　The boy is about 12 years old . 这个男孩约12岁。

　　句型52：keep ... from doing

　　The heavy rain kept us from starting out. 大雨阻止了我们出发。

　　句型53：with one’s help...

　　With Tom’s help，I’ve come to America to study further. 在汤姆的帮助下，我来美国深造。

　　句型54：I don’t think ...

　　I don’t think any of them is interesting. 我认为他们中任何一个都无趣。

　　句型55：What’s the population of ...？

　　What’s the population of Germany ？德国的人口有多少？

　　句型56：prefer to do … rather than do

　　They prefer to buy a new one rather than repair it. 他们更喜欢买一辆新车，而不愿去修理它。