1、I’ve just lost my keys.我刚丢了钥匙。

2、Since when have you planted so many young trees?从什么时候开始你种植了这么多小树的？

3、I have read the novel.我看过这部小说了。

4、They have gone out.他们已经出去了。

5、I have bad news. I have lost my job.有坏消息，我丢了工作了。

6、This is the first time I have been here.这是我第一次到这儿。

7、They haven’t finished yet.他们还没结束。

8、How many times have you been to Singapore?你去过新加坡几次？

9、My momhas never travelled by air.我妈妈旅游从来没有坐过飞机。

10、I've been doing my homework.我一直在做作业。