15．It turns out that nodding off in class may not be such a bad idea after all，as a new study has shown that going to sleep shortly after learning new material is the best way to remember it．
According to US lead author Jessica Payne，a psychologist at the University of Notre Dame in Indiana，nodding off after learning something new is like‘telling'the sleeping brain what to keep in memory．Along with colleagues，she studied 207students who habitually slept for at least six hours per night．Participants were randomly assigned to study declarative，semantically related or unrelated word pairs at 9a．m．or 9p．m．，and returned for testing 30minutes，12hours and 24hours later．
Declarative memory refers to the ability to consciously remember facts and events，and can be broken down into episodic memory （memory for events） and semantic memory （memory for facts about the world）．People routinely use both types of memory every day-recalling where we parked today or learning how a colleague prefers to be addressed．At the 12-hour retest，memory overall was superior following a night of sleep compared to a day of wakefulness．At the 24-hour retest，with all subjects having received both a full night of sleep and a full day of wakefulness，subjects'memories were superior when sleep occurred shortly after learning，rather than following a full day of wakefulness．
"Our study confirms that sleeping directly after learning something new is beneficial for memory．What's novel about this study is that we tried to shine light on sleep's influence on both types of declarative memory by studying semantically unrelated and related word pairs"，Payne said．"Since we found that sleeping soon after learning benefited both types of memory，this means that it would be a good thing to rehearse any information you need to remember just before going to bed．In some sense，you may be"telling"the sleeping brain what to consolidate （巩固）．"
41．What does the underlined phrase nodding off mean？A
A．Going to sleep．
B．Arguing with others
C．Asking questions．
D．Answering questions．
42．How many times will the participants tested？C
A．At least once B．At least twice
C．At least three times D．At least four times
43．What can we infer from the passage about the study？D
A．Jessica Payne carried out the study all by herself．
B．The 207students were forced to sleep at least six hours per night．
C．Participants were asked to memorize things according to strict rules．
D．Participants could memorize what they learnt right before they slept best．
44．What would Payne advise us to do？B
A．Memorize things after we have a good sleep．
B．Memorize things just before our sleep．
C．All the students go to sleep in class．
D．Memorize things at mid-night．
45．The text is most probably aA．
A．science report B．book review
C．science fiction story D．newspaper advertisement．
分析 本文是一篇科教类阅读．文章主要介绍了一项新的研究，表明了课堂上打瞌睡也许并不是一件坏事，学习新的东西后马上睡觉会对记忆有好处．
解答 41．A 词义猜测题．根据第一段as a new study has shown that going to sleep shortlyafter learning new material is the best way to remember it．可知一项新研究显示学完新知识后马上打个小盹是最佳的记忆方法．由此推知，nodding off的意思是"睡觉，打盹"．故选A．
42．C 细节理解题．根据第二段and returned for testing 30minutes，12hours and 24hours later．可知他们学完后在30分钟、12小时或24小时后回来做测试．由此推知，他们将参加实验至少三次．故选C．
43．D 推理判断题．根据第三段subjects'memories were superior when sleep occurred shortly after learning，rather than following a full day of wakefulness．可知那些在学习后不久就入睡的人比那些学习后过了一整个白天才睡觉的人记忆效果更好．由此推知，参与者在睡觉之前可以记住他们学到的东西．故选D．
44．B推理判断题．根据第一段和最后一段可知新的研究表明学习新的东西后马上睡觉对记忆有好处．由此推知，Payne会建议我们在睡觉之前记忆东西．故选B．
45．A文体推断题．从文章内容来看本文主要介绍了一项新的研究，表明了学习新的东西后马上睡觉会对记忆有好处．很明显这是一篇科学研究报告．故选A．
点评 本文考察学生的理解推断能力以及细心程度，只要抓住文章的关键词，采用寻读的方法查找细节，就能找到正确答案．
