1. is
2. Are they happy
3. wrote
4. didn't go/was
5. Did his brother come/didn't come/was
6. had
7. went/took
8. Do you often go/go
9. why didn't Susan notice/were/didn't see
10. do you like
11. Did she buy/didn't buy
12. What does your sister do/meets
13. didn't understand
14. moved
15. is/ate
16. Did the sell/ I don't know
17. forgets/ leaves
18. What is the weather like
19. was
20. draws