--- Look out for the door.--- Why?--- Bill ______ the door.
举一反三
- Why not ( )at the back door?
- The_________stood on his head, begging from door to door. (beg)
- Why do people hang artemisia above the door?
- A poor boy was trying to pay his way through school by selling goods door to door.
- C. Leave the door of the copy room open, when there is a meeting or people working next door.