Fill in the blanks

16. The students _________ their books in their bags.

a) keep

b) keeps

c) keeping

d) kept

17. She _________ her brother how to swim.

a) teaches

b) teach

c) teaching

d) taught

18. We _________ to go on a trip next month.

a) planned

b) plan

c) planning

d) plans

19. The baby _________ asleep during the movie.

a) fall

b) falls

c) falling

d) fell

20. My sister _________ in the garden right now.

a) works

b) work

c) working

d) worked