I called you at 4:00 yesterday afternoon, but no one answered.—Sorry, I ______ with my friends at that time.
Does anyone know _______ girl with a book in her hand over there?—I’m afraid no one knows.
My aunt works_____ a magazine_____ a reporter.[ ]
Shall we go out for a walk?—Sorry, I can’t. I _______ my homework.
I think __________ people will go to Shanghai for the EXPO 2010.