4. The whole country held its breath to see who would win the election.

3. I can’t forgive myself for not seeing my mother before she died.

2. I must apologize to you for not being able to meet you.

1. We invited her to dinner but she hasn’t turned up.

12. 很明显，如果每一个人都能节约一滴水，我们就能救活很多人。

Keys：

11. 这首歌让我想起了我的童年时代。

10. 发现有人走过来，他们停止交谈站起身来。

9. 当我有困难时，他总是第一个主动帮忙。

8. 旧社会由于很穷，很多父母供不起孩子上学。

7. 你本来能帮助那位老人的，为何像个傻子似的只是站在那儿呢？