How come you stepped into the lab with your shoes on? You’re ________to take them off before you enter it. I told you so.
It was after he got what he had wanted very much _______ he realized it was not important.
This year this factory has produced ________ cars as it did last year.
The famous writer our Chinese teacher often referred ________ at our school yesterday.
Please go ______ the ship quickly. There is only ten minutes left.
The question came up at the meeting _______ we had enough money for our research.