选择括号内恰当的单词或词组填空，使句意完整
——            （Which , Whose）schoolbag is that?
——It’s Tom’s.
—When did you hear the news?
—I know nothing about it              （until , after）my friend told me.
One of my friends              （are , is）a doctor.
My mother is feeling              （badly , terrible）. She must have a cold.
We’re OK. Don’t              （worried , worry）about us.