-- _____is that used for?---_____ the floor.
The girl on the bus began to sing a pop song and soon all the others_________.
.The new building is_________to be completed before the end of this year.
—Waiter!—Yes?—Three_________,please.
This pair of shoes looks nice.How much will you_________ for it?
I wonder how long it will be before he_________ at the meeting.