5.　　 ---______ you ______ (have) your supper?

---Yes, I have.

4.　　 What do you think Li Ping_______(do) right now?

3.　　 ---Where is my friend? ______you _______ (see) her?

---Yes, I ______ her three minutes ago. But she ______(go) to the post office. I think she ______(be) back soon.

2.　　 ---_____you ______(return) the book to the library yet?

---Yes, I _____. I ______(return) it yesterday afternoon. The book ______(be) very interesting.

1.　　 ---What _____ she ______ ( do ) last Sunday?

---She ______(listen) to the radio.

5.　　 为什么没有人从别的行星上给我们发送信息呢？

Why has ______　 _______　 _______ other planets _______ us a message?

4.　　 弄清楚宇宙有多大是困难的。

It is hard ______　 _______　 _______ large the _______ is.

3.　　 科学家们已经在宇宙中发现了许多别的星系。

Scientists ______　 _______　 _______ many other ______ in the _______.

2.　　 我们还没有在其他行星上发现生命。

We haven’t ______　 _______ on other ______ in the ______.

1.　　 科学家们认为世界上存有生命已有几百万年的历史了。

Scientists _____　 ______ there has been life _____　 _____ for ______　 ______ years.