Chen Hui was chewing gum ________.
—Could I open the door? —______. It’s very cold outside.
I think these students should do ______ part in keeping the class-room clean.
When my mother ______ home, I was making some cards.
I used to ______ English in the evening. Now I’m used to ______ it in the morning.
Look! Bill is not happy. Let’s go and ______. A wake him upB. cheer him up C. dress him up D. call him up