Which sign means “Don't eat in class.”?
_____ he was tired , ____ he didn’t stop working .
The air in Lanzhou is getting much _____ now than a few years ago .
The teacher is speaking. Please stop _____ and listen to him.
--May I borrow this dictionary ? ---Sorry. This is not _____. It’s Lily’s .
---_____do you go to visit your grandma ?---Twice a month