48.The phrase" to sleep on a problem" in Paragraph 1 most likely means to______.

　　A.pay full attention to a problem

　　B.wait until later for a decision

　　C.sleep to forget a problem

　　D.have difficulty sleeping

　　49.In the study by the US research team, students were asked to______.

　　A.put together words of similar meanings

　　B.remember words and their meanings

　　C.show their knowledge of words

　　D.make up lists of related words

　　50.Which of the following may be easier to remember?

　　A.Themes learned right before the tes

　　B.Rules from personal experience

　　C.Words learnt before a good slee

　　D.Ideas stored together in the brai

　　51.What may be the importance of the research?

　　A.It shows sleep may help us manage imformatio

　　B.It helps find out the common themes of word

　　C.It tells us that more sleep can improve healt

　　D.It proves the value of old-fashioned advice

　　KEYS：

　　40-45.CADADA　　46-51 .CCBBCA