第一句：I'll let him know.
A: I wonder if you could give Mr. Wang a message for me.
B: Yes, certainly.
A: There will be a very urgent meeting at 3 o'clock this afternoon and I would like him to attend.
B: I'll let him know.
第二句：Shall I ask him to call you when he is free?
A: I don't think the meeting will go on much longer. Shall I ask him to call you when he is free?
B: Yes, that would be nice.
A: Could I have your phone number, please?
B: Yes. 021-64358796.
You'll be hearing from Mr. Green later in the morning then, Mr. Smith.