—You should be careful when _______.—Yes, I will. I’d like to know when ________ to have a rest.
---You’re late! You were ____to be here an hour ago. --- Sorry, Mr. Hu.
Mike couldn’t find Kelly ____before the bus left, so he didn’t get on the bus.
--- You can’t ____what a terrible weekend I had. I had a bad cold. --- I’m sorry to hear that.
--- What about going hiking this weekend? ---Sounds good. The weather is _____.
There will be _____ pollution this year than last year.