第一节 听下面5段对话。每段对话后有一个小题，从题中所给的[A]、[B]、[C]三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。 Why did the man start the quarrel with Mary

A．the brain begins processing and storing memories just before it's time for bed
B．parts of the brain that we have not used to learn become active again during sleep
C．the processing continues only when they're thinking about or doing other things.
D．each task requires different parts of the brain to learn.

A．a good night's sleep helps your brain permanently file away lessons learned during the day.
B．the brain has to wait until the lights are out to begin processing those memories
C．perhaps it's safe for anyone to get plenty of sleep when it has not been proved unnecessary for memory
D．attracting the subjects doesn't affect their ability to store memories.