—I really like the modern digital camera you lent me last week. — . —And thank you very much for letting me keep it so long.
Mother: Bob is sure ___ tonigh. Father: Don't be so sure ___ it.
We found ___ for us to finish the work within two days.
Professor Smith ___ China yesterday.
I’m writing to you and ask whether you’d like to give us ___ how to learn English.
I wonder why he hasn't __ any of my letters for such a long time.