The printer is of good quality. If it ______ break down within the first year, we would repair it at our expense.
18. ---- Are you free after school? ---- Sorry. I’ve planned to treat a friend of mine to dinner _______for his help.
17. Is this research center _________ you met some foreign guests last week?
16. ---- How long has this church been in service? ----_________1682, I’m afraid.
15. _______ the day went on, the weather got worse, which made it impossible for them to go down the mountain.
14. ---- Is it Tom that playing basketball? ---- It __________ be him. He is so crazy about basketball.