It is often said that the best way to solve a hard problem is to sleep on it.Is it true？A new study shows that it is.
   A team of scientists in the US found that sleeping is useful to help you solve problems.They did an experiment on university students.They asked students to solve 42 difficult problems on the first day.Students worked on each problem when listening to different music.Students could try to remember the music they heard when solving the problems.By the end，there were still six problems left.
   The students then went back home to sleep with special music players.They played music linked（聯(lián)系）with the unsolved problems when the students were in the slow-wave sleep stage （時期）.This stage is when people are likely to dream and reorganize memories（重組記憶）.
   The next morning，the students tried the unsolved problems again.Scientists found they were 55 percent more likely to solve jye.aim.The music activated （激活） the memories they had of the problems when they were sleeping.With its help，they were able to "work" on the problems in their sleep.
   Scientists have found that sleep can not only strengthen （強化） memory，but also help us organize and send information.This study is more evidence （證據(jù)） of these findings.So the next time you face a difficult problem，sleep on it.Play some music to help yourself think of the problem.

（1）According to the study，

B

B

can help us solve problems.
A．working
B．sleeping
C．memory
D．practice
（2）What order should the following steps go in，according to the passage？

A

A

①Students listened to music when they slept.
②Students were asked to solve problems when listening to music.
③Students tried the unsolved problems again.
④Students left six problems unsolved.
A． ②④①③
B． ②④③①
C． ①②④③
D． ②①④③
（3）Scientists found that

D

D

after sleeping.
A．students remembered the music they heard
B．students forgot how to solve some of the problems
C．students remembered the unsolved problems clearly
D．students were more likely to solve the unsolved problems
（4）What do we know from the last paragraph？

C

C

A．No scientists have studied sleep before.
B．Sleeping can't help us solve any problems.
C．Listening to music can help us solve problems.
D．People can always remember their dreams clearly.