–Mr Li always spends lots of time explaining things ______ us.–I agree. He’s patient enough to repeat them _______ us.
Miltie________a picture when Mr.Green came in.
—Always look around________you cross the street,David.—OK.I know,Mum.A.untilB.beforeC.unless
The thieves ran away at once when the burglar alarm(防盗报警器)________.
—Did you see Mr Smith when you were in France?—No.When I________France,he________to China.
He told us that he________the letters in the morning.