mustn't [ˈmʌsənt]
mustn't → must not, → must
I. must [mʌst] 动词 助动词
1. must (be obliged):
2. must (be required):
3. must (should):
4. must (be likely):
5. must (be certain to):
6. must (be necessary):
7. must (show irritation):
II. must [mʌst] 名词 no pl