题目内容：
提示：Peter给Johnson教授打电话请病假，接电话的是教授的助手Sally。
( Peter = P; Sally = S)
P: Hello! This is Peter speaking. 51 ,please?
S: I'm sorry. Professor Johnson is not here at the moment. This is his assistant,Sally. 52 ? P: Yes. Please tell the professor that I'd like to ask for sick leave for tomorrow.
S: Sorry to hear that. May I ask 53 with you?
P: I'm running a fever. I've caught a cold.
S: Oh, 54 ?
P: No, not very serious, but the doctor told me to stay in bed and have a good rest.
S: I see. I'll 55 as soon as he comes back.
P : Thank you. Goodbye !
S: Bye!
第（51）题
答案解析：