问题
Whose book is this—It ________be Mary’s. J. K. Rowling is her favorite writer.—No, it ______ be hers . She never brings novels to school.
A:may, mustn't
B:can; can't
C:must; can't
D:must; mustn't;
B:can; can't
C:must; can't
D:must; mustn't;
正确答案是：
