I. Choose the best answer to complete each of the following sentences.
21. The dogs _____________ fed before they went to the party.
A. has B. have been C. had been D. having been
22. The car was dirty. They _____________ it for weeks.
A. hasn't cleaned B. haven't cleaned C. hadn't been cleaned D. hadn't cleared
23. It _____________ her 10 minutes to do this exercise yesterday morning.
A. made B. took C. cost D. lost
24. Frank is capable _____________ doing better than he is doing now.
A. of B. at C. with D. in
25. The scheme has been set up to help _____________ people.
A. home-made B. homeless C. house-style D. houseful
26. We're _____________ the evening around a Japanese theme.
A. organizing B. organizer C. organization D. organized
27. The pollution problems _____________ since last month.
A. has discussed B. have discussed C. has been discussed D. have been discussed
28. When they got home last night. They found that someone _____________ into the house.
A. had broken B. had been broken C. has broken D. has been broken
29. How many languages are _____________ in Chinese?
A. speak B. speaking C. spoken D. speaker
30. The woman sitting next to me on the plane was very nervous. She _____________ before.
A. hasn't flown B. hadn't flown C. didn't fly D. doesn't fly