P: Hello! This is Peter speaking. _____, please?S: I'm sorry. Pr

P: Hello! This is Peter speaking. _____, please?S: I'm sorry. Professor Johnson is not here at the moment. This is his assistant, Sally. _____?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 _____ with you?P: I'm running a fever. I've caught a cold.S: Oh, _____?P: No, not very serious, but the doctor told me to stay in bed and have a good rest.S: I see. I'll _____ as soon as he comes back.P: Thank you. Goodbye!S: Bye!_____.
【正确答案】：tell him about it / let him know
【题目解析】：Sally答应Peter尽快告知教授他的来电内容。