Problem: Given the question: W: Really? I'd like to see that, too. What was said before this conversation?
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The answer is:
M: There is an exhibition about planes and satellites.

Problem: Given the question: M: It is the Chemistry and Physics lab. What was said before this conversation?
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The answer is:
W: Is this the English class?

Problem: Given the question: W: She had phoned to tell me that before she went away. What was said before this conversation?
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The answer is:
M: When I phoned Rose, her sister said she had gone out.