Problem: Given the question: W: If we wait for John, we might be here all night.  What was said before this conversation?
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The answer is:
M: Everybody is here except John. Shall we start the meeting?


Problem: Given the question: Woman: Since there isn't any homework for today, let's go to the movies instead of going home.  What was said before this conversation?
++++++++++++++++++++++++++++++++
The answer is:
Man: Where shall we go?


Problem: Given the question: M: I'll meet you for dinner after I've been to the airport.  What was said before this conversation?
++++++++++++++++++++++++++++++++
The answer is:

W: If you're going to the airport, what about our dinner?