857.______,please try your best to solve the problem in time.
A.Ought you get into trouble
B.Must you get into trouble
C.Can you get into trouble
D.Should you get into trouble
858.What _____ it be?
It _____ be a man,for it is not moving.It _____ be a dustbin,I think.
A.can;may;must
B.can;can't;must
C.can;must;can
D.may;may not;could
857.答案是D;含有if的虚拟语气句，当省略if时，往往将should/had/were提到主语之前构成倒装句。
858.答案是B;考查情态动词表示推测的用法。第一空can表示推测用于疑问句；第二空can用于否定句；第三空表示肯定的推测用must。
