Advice to “sleep on it” could be well founded, scientists say．After a good night’s sleep a problem that couldn’t be solved the night before can often appear more manageable, although the evidence until now has been anecdotal （个人体验的）．But researchers at the University of Luebek in Germany have designed an experiment that shows a good night’s sleep can improve insight （顿悟） and problem-solving．
“If you have some newly-got memories in your brain, sleep acts on these memories and restructures them , so that after sleep the insight into problem which you could not solve before increases,” said Dr Jan Born , a neuroscientist （神经科学家）, at the university．To test the theory, they taught volunteers two simple rules to help them turn a string of numbers into a new order．There was also a third, hidden rule, which could help them increase their speed in solving the problem．The researchers divided the volunteers into two groups: half were allowed to sleep after the training while the rest were forced to stay awake．Dr Jan Born and his team noticed that the group that had slept after the training were twice as likely to figure out the third rule as the other group．“Sleep helped,” Born said in a telephone interview．“The important thing is that you have to have a memory representation in your brain of the problem you want to solve and then you sleep, so it can act on the problem．” But Born admitted that he and his team don’t know how restructuring of memories occurs or what governs it．Pierre Maquet and Perrine Ruby of the University of Liege in Belgium said the experimental evidence supports the anecdotal suggestions that sleep can help develop creative thinking．Although the role of sleep in human creativity will still be a mystery, the research gives people good reason to fully respect their periods of sleep, they added．
1．The underlined phrase “sleep on it” in Paragraph 1 probably means ．
A．to delay deciding something until the next day
B．to get as much sleep as possible
C．to go on sleeping without being disturbed
D．to sleep till after the time you usually get up in the morning
2．Jan Born and his team carried out the experiment through _____．
A．comparison B．interview C．survey D．imagination
3．It can be inferred from the passage that ______．
A．people should sleep so long as they have time
B．sleep is the only way to solve hard problems
C．people have various periods of sleep
D．people know how sleep reconstructs memories
4．What would be the best title for the passage?
A．How Sleep Works B．Sleep Helps Solve Problems
C．No Evidence, But Well Founded D．Born’s Discovery On Sleep