单选题 Scientists say they now have proof to support the old-fashioned advice that it's best to sleep on a problem. They say sleep strengthens the memory and helps the brain organize the masses of information we receive each day.
Lead researcher Bob Stickgold at the Harvard Medical School said, "Sleep helps us draw rules from our experiences. It's like knowing the difference between dogs and cats. even if it's hard to explain. "
The US research team studied how well students remembered connections between words and symbols (象征), reports New Scientist. They compared how the students performed if they had had a sleep between seeing the words and having the test, and if they had not slept. They found that people were better able to remember lists of related words after a night's sleep than after the same time spent awake during the day. They also found it easier to remember themes (主题) that the words had in common. But they forgot around one in four more themes if they had been awake.
Prof. John Groeger, of Surrey University's Sleep Research Centre, said, "People have been trying for years to find out what the purpose of sleep is, as we know that only certain parts of it have a restorative (有助恢复的) value. "
"We form and store huge numbers of experiences in the head every day, and sleep seems to be the way the brain deals with it all. /

单选题 The phrase "to sleep on a problem" in Paragraph l 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

【正确答案】 B

【答案解析】[解析] 语义题。由整篇文章关于睡眠的功效可知，这个短语的意思是等到以后再解决。所以正确答案是B。

单选题 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

【正确答案】 B

【答案解析】[解析] 细节题。由文章第三段第一句可知，在研究中学生们被要求记住单词和意思。所以正确答案是B。

单选题 Which of the following may be easier to remember?
A. Themes learned right before the test.
B. Rules from personal experiences.
C. Words learnt before a good sleep.
D. Ideas stored together in the brain.

【正确答案】 C

【答案解析】[解析] 细节题。由文章第三段第三句可知，睡前学过的单词更容易记住。所以正确答案是C。

单选题 What may be the importance of the research?
A. It shows sleep may help us manage imformation.
B. It helps find out the common themes of words.
C. It tells us that more sleep can improve health.
D. It proves the value of old-fashioned advice.

【正确答案】 A

【答案解析】[解析] 推理题。由文章第一段和最后一段可推理出，睡眠帮助我们组织信息是研究的重要之处。所以正确答案是A。