__________ be late for the first class, Bill took a taxi instead of riding to school that morning.
It was proved that drunkdriving was________for the death of five people in Nanjing.
We haven’t dicussed yet _______ we are going to place our new furniture.
---Do you think it’s a good idea to make friends with your students? ---_____, I do. I think it’s a great idea.
Many beautiful fish are disappearing____ the severe(严重的) pollution.
---- Where does Mr. Black live ? Can you guess? ----- Sorry, I can’t guess ________.