问答题 根据中文提示，把对话中缺少的内容写在线上。这些句子必须符合英语表达习惯。打句号的地方，用陈述句；打问号的地方，用疑问句。
　　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 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!（）