听力原文:M: Miss Hanson, thank you for sending me this note. I'm sorry to hear Mario is be
W: I'm not sure what's happening to Mario. He's usually an excellent student. He completes all his work and he's quiet in class. Then, last month, he just changed.
Q: What can you infer from the conversation?
(19)
A.The woman is the man's boss.
B.The man is the woman's husband.
C.The woman is the headmaster of a school.
D.The woman wants to know something about a student.