题目

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 whi已知x≠0，等于A.B.C.D.