6. Our room must ___ clean.
举一反三
- Our room must ___ clean.
- Our room must ( ) clean. A: to keep B: be keeping C: be kept D: keep
- This room is not clean. It is very_____. A: tidy B: untidy C: clean D: not dirty
- ---Must I clean the room now? --No, you __________.
- The room is so clean. He ________ have cleaned it yesterday evening. A: will B: need C: can D: must