look the man at the gate___be our headmaster .he is always standing there every morningno,it ____be him .he is holding a meeting in the office now A.must can't B must mustn't C can't can't Dcan't musn't
问题描述：
look the man at the gate___be our headmaster .he is always standing there every morning
no,it ____be him .he is holding a meeting in the office now
A.must can't B must mustn't C can't can't Dcan't musn't
答
A.
第一句must表示猜测,相当与"应该是谁谁";
第二句can't表示否定, 意思是"一定不(会)是".
答
can't 看门口的人不可能是我们校长,他每天早上都站在那里
mustn't是不允许的意思,不符合句意