Problem: Given the question: M: We should wait for the weather report, but I believe it will clear off tomorrow. What was said before this conversation?
++++++++++++++++++++++++++++++++
The answer is:
W: Shall we go for a picnic tomorrow?

Problem: Given the question: W: I'm sorry I'm late, but I was waiting for you at the in formation desk. It's lucky I've found you here on the platform. What was said before this conversation?
++++++++++++++++++++++++++++++++
The answer is:
M: Where've you been all this time? The train's about to leave!

Problem: Given the question: M: Oh,dear,my back's killing me. What was said before this conversation?
++++++++++++++++++++++++++++++++
The answer is:
W: How are you,Brandon?