It is written clearly in the requirements that all passengers check onto board t
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It is written clearly in the requirements that all passengers _______ check onto board thirty minutes before the plane takes off．
A. may??? ???? B. can? ?? ? ? C. will ????? D. shall
试题答案
【答案】
D
【解析】
四个选项分别表示可以、能、将要和应该，根据题意选D，要求中清晰地写明了，飞机起飞前三十分钟，所有乘客都应该检查后登机。