—Who______ it be that is knocking at the door?—I—Who______ it be that is knocking at the door?—It ______ be Father,but I’m not sure.A.can; must B.can; may C.must; can D.may; must
问题描述：
—Who______ it be that is knocking at the door?—I
—Who______ it be that is knocking at the door?
—It ______ be Father,but I’m not sure.
A.can; must B.can; may C.must; can D.may; must
答
b