1.
She used to
be a history teacher.
2.
It's
our duty to keep our environment clean and tidy.
3.
If you
get a chance to go, take it.
4.
Which
of these do you think is the second most useful invention?
5.
Most
business letters around the world are written in English.
6.
There
are twenty more trees to be planted.
7.
There will
be hardly enough space for anybody else.
8.
It
is necessary to take medicine on time.
9.
They
played carelessly , and they deserved to lose.
10.
She
decided to buy a digital camera online so that it could be sent to her.
11.
夏威夷以它那美丽的海滩而著名。
12.
赶快，不然我们要迟到了。
13.
他对潜入深海很感兴趣。
14.
这听起来有意思。
15.
中华人民共和国是什么时候成立的？
16.
很多星星因为太遥远而看不见。
17.
我的网球皮鞋穿破了。
18.
我们对我们自己很生气
19.
给予比接受好。
20.
世界的人口增长越来越快。
