题文
Excuse me ,sir. You ______ open the door before the train stops.
| A.mustn’t | B.needn’t | C.may not | D.don’t have to |
Excuse me ,sir. You ______ open the door before the train stops.
| A.mustn’t | B.needn’t | C.may not | D.don’t have to |
试题篮
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