A: Would you mind my smoking here?B: Look at that sign. It says, “No smoking.”
You will find you can enjoy so many books if you English.
Don’t come into the lab ________ you are asked to.
My uncle has been taught in this school _______ he was twenty years old.
Don’t worry, sir. I’m sure I can run _____ to catch up with them.
The sports meeting _________ until next month.