1. is studying, forgets
2. go, feel
3. does not remember, doesn't seem
4. is watching, watches, goes
5. are you doing
6. am trying, listen
7. is washing
8. washes
9. do you always lock
10. is snowing, seldom snows
11. is seeing
12. has
13. think
14. am thinking
15. costs
16. is raining, don't have
17. sleep, get up, brush, have, go, never miss
18. doesn't want, are going
19. does the plane take off
20.are having
