We should go to school at 8:00 ______________ school mornings.
--- All the clerks went home _____ Mr. Wang. Why?--- Because he had to finish his work.
--- Can you_____ your little brother? I’m busy now.--- OK. I’ll do it right now.
--- You always spend only a little time on your study. You really _____ me down.--- I’m sorry, Mum. I won’t do that again.
---There are many volunteers ______ are helping the children in Sichuan.--- And most of them are college students.
---If there are ______ people driving , there will be ______ air pollution.--- Yes, the air will be fresher.