1) I don't think that it's a good idea. He hasn't left the house yet. We haven't seen for ages! Don't eat until they will come. She doesn't go swimming on Mondays.
2) are you taking part in the exhibition? Do you mind if he come? What are you talking about? May be we should tell it to her? Do you believe she leave her job?
3) he came without knocking at the door. This house needs painting. She likes cooking. It's pleasure to work there. Your son succeeds in studying. Take care of them when I leave.