16. (she/ need) ______ some stamps for overseas mail?
17. How much (be) ______ two local stamps?
18. I hope I (meet) ______ the former President of the U.S. Barrack Obama one day.
19. His brother often helps him (do) ______ his homework.
20. Look at the black cloud! It (rain) ______. We should stop to find a shelter.
21. Lan and her friends (rehearse) ______ a play at the moment.
16 does she need
17 are
18 will meet
19 do
20 is going to rain
21 are rehearsing