–I could not start my car this morning due to the cold weather. --No wonder you were late. You ___ have used mine. I was not using all the morning.
He commanded that all the gates _____when it was getting dark in case thieves came in .
Mr. Black has been teaching English in a middle school _____ he came to China.
. — What's that noise? —Oh , I forgot to tell you. The new machine ________
—Sorry. I didn’t break the plate______. —It’s OK. Don’t worry about it.
_____ your classmates and you will make more good friends.