16. ― Lucy, these books are all over the place. Are they yours?
― No, these are________ books, not________.
A. their; ours B. theirs; ours C. theirs; our D. their; our
17. I hope you ________fun visiting the museum with us tomorrow.
A. to have B. having C. have D. will have
18. The building there ______________ twenty- five floors.
A. are B. is C. have D. has
19. After reading for an hour, you’d better ________ the green trees for a minute or two.
A. look out of B. look out at C. look out from D. look for at
20. ― ________ is your school from your home?
― Twenty minutes’ ride.
A. How far B. How long C. How often D. How soon
