9. I don't know what_______(do) next.

8. Let’s invite Joe and Tom_______(play) tennis.

7. The teacher told us that light_________(travel) faster than sound.

6. I am better than her at_________(swim).

5. If you don’t have a ticket for tomorrow's concert, they_________(not let) you in.

4. Is the plane able________(take) off in such weather?

3. Do you think________(raise) a child is more difficult than keeping a pet?

2. When I met her in the street, she________(talk) with a friend.

根据句义用所给动词的正确形式填空，必要时可加助动词。

1. Please give it to Linda if she_________(come) tomorrow.

20. People should care for animals in___________(dangerous).