Question 7. Jack found an old corn while he _______ in the garden.

A. works

B. was working

C. is working

D. working

Question 8. When I was a boy, I ________ swimming every morning.

A. use to go

B. used to go

C. used to going

D. use to go

Question 9. It took us three days ________ our project on how to reduce water pollution.

A. to complete

B. to complete

C. completing

D. to completing