-- _____is that used for?---_____ the floor.
—Why did you leave the lights burning? —Heavens! I guess I to turn them off.
The sandstorm _ for several days,which left a terrible sight across the west.
Mary felt from the outside world, since she lacked an Internet connection and couldn’t receive any e-mail.
How long do you think it will be China becomes a rich and harmonious country?
If Tom’s wife doesn’t go to the party, .