.Susan’s parents have bought a large house with a swimming pool. It ______be very expensive.

--______do you spell your family name?—C-L-A-R-K,Clark. 

Mr. Baker, a number of students want to see you. _______ they wait here or outside?

––I didn’t go to work yesterday because my car broke down.––You _____ mine. I wasn’t using it then.

--- The fog is so thick that the express way ____ have been closed. --- You are right. I ____ have thought of that. Now we have to take another road.