题目1.
This coat isn't yours.Whose( )it be?
A.can B.may C.must D.will
答案选的是B，我选的是A
题目2.
There's somebody at the door,( )it be jim?
No,it( )be him.It's just seven o'clock. It's too early.
A.May,can't B.Will,won't
C.May,musn't D.Must, may not
答案选的是A，但我选择的是D。
但我疑惑的是，我看到一本资料书上说，May在表示怀疑，猜测时，不用于问句，而这两道题中的May都是表猜测。但答案为什么这么选择呢？我所选择的选项又哪里错了，请英语高手解答！

This coat isn't yours.Whose(B )it be?
A.can B.may C.must D.will
may+be表“也许，可能”，must表肯定的猜测，can表否定的猜测.所以选B
There's somebody at the door,( )it be jim?
No,it(A )be him.It's just seven o'clock. It's too early.
A.May,can't B.Will,won't
C.May,musn't D.Must, may not
may用在疑问句中是"会,可能",can't表"不可能",mustn't表"不可以,不允许",这里回答是"No",就说别人认为那一定不可能是Jim,所以不选mustn't.这里对"将来"没有特别强调,考察情态动词的用法的理解.所以选A.