13．Previous studies have suggested as many as 70percent of college students get insufficient（不充足的）sleep．But new data released today that analyzed sleep habits of college-age users of Jawbone's UP fitness tracker suggests otherwise．
Jawbone looked at sleep data from college-age users who wear the company's UP fitness trackers and found that they actually average just over 7hours of sleep per night on weekdays and 7.38hours on weekend nights．The data comes from 18，498college-age users from 137schools across the country who wear the device and accounts for 1.44million nights of sleep data recorded by those individuals between 2013and 2016．Here are four more points about the research：
1．People at high-achieving schools tended to have later bedtimes
The data analytics team at Jawbone was also able to separate out sleep data for each school with UP wearers reporting data．They found that the tougher the school，according to the U．S．News ranking，the later the average college-age UP wearer at that school goes to bed．
2．Still，7hours may not be enough sleep
While the data from Jawbone may be encouraging，considering that previous research has found that some students sleep only 5.7hours a night on average．But Neil Kline，a sleep physician，points out that even this higher number isn't sufficient．"There is much data that suggests that this age group needs more than seven or 7.5hours of sleep on average per night，"Kline claimed．
3．The data doesn't include naps
Another point，Kline said，is that the data doesn't include naps．Total daytime sleep-napping-tends to be difficult to account for because naps can be short and easily forgotten，he said．But they do affect total sleep．
4．Fitness-tracking students aren't exactly the norm
It's also important to note that the data from Jawbone comes from college-age people who purchased and used Jawbone UP fitness tracking devices，which means that the participants in this research do not necessarily make up a representative sample（樣本）of college students in terms of socioeconomic status or lifestyle factors．
28．What does the underlined sentence mean in Paragraph 1？D
A．New data has the same results as the previous one．
B．New data and the previous one have many things in common．
C．New data from Jawbone may astonish most college students．
D．New data suggests that college students spend more time sleeping．
29．According to the new data，a student who does well in academic performance may probably sleepB．
A．less than 5.7hours a night
B．less than 7.5hours a night
C．early at night
D．over the night
30．Which of the following statements is TRUE according to the passage？A
A．The sample of college students is far from enough．
B．College students usually don't have naps at all．
C．College students sleep only 5.7hours a night on average．
D．Every college student across the country takes part in the research．
31．What is the author's purpose in writing this passage？C
A．To show the importance of sufficient sleep at night．
B．To explain why college students can't get sufficient sleep．
C．To tell readers some data about college students'sleep per night．
D．To offer college students some tips on handling insufficient sleep．
分析 本文屬于說明文閱讀，寫出了先前的研究大部分大學(xué)生睡眠不足與最新的關(guān)于大學(xué)生睡眠時(shí)間的研究的對比（數(shù)據(jù)不包括午睡），告訴讀者應(yīng)該保持充足的睡眠．
解答 28．D 推理判斷題，根據(jù)第一段Previous studies have suggested as many as 70percent of college students get insufficient（不充足的）sleep．But new data released today that analyzed sleep habits of college-age users of Jawbone's UP fitness tracker suggests otherwise．可知先前的研究表明許多大學(xué)生睡眠不足，而新的數(shù)據(jù)表明，大學(xué)生們花更多的時(shí)間睡覺，故選D．
29．B 推理判斷題，根據(jù)第四段"There is much data that suggests that this age group needs more than seven or 7.5hours of sleep on average per night，"Kline claimed．
可知根據(jù)新的數(shù)據(jù)，這個年齡的學(xué)生需要多余7或7.5個小時(shí)的睡眠，因此可推斷一個在學(xué)習(xí)成績上表現(xiàn)很好的學(xué)生可能睡的少于7.5個小時(shí)，故選B．
30．A 細(xì)節(jié)理解題，根據(jù)最后一段which means that the participants in this research do not necessarily make up a representative sample（樣本）of college students in terms of socioeconomic status or lifestyle factors．可知這項(xiàng)研究的樣本是有限的，因此A正確；誤解分析：由第五段Another point，Kline said，is that the data doesn't include naps．可知這個研究不包括午睡，不是大學(xué)生不午睡，因此B錯；由第四段 some students sleep only 5.7hours a night on average有些學(xué)生只睡5.7小時(shí)，因此C錯；而D項(xiàng)并不是全國每一個大學(xué)生都參加了這一研究；故選A．
31．C 主旨大意題，通讀全文發(fā)現(xiàn)這篇文章主要向我們介紹了現(xiàn)在大學(xué)生每晚睡眠時(shí)間的一些數(shù)據(jù)，故選C．
點(diǎn)評 考查學(xué)生的細(xì)節(jié)理解和推理判斷能力．做細(xì)節(jié)理解題時(shí)一定要找到文章中的原句，和題干進(jìn)行比較，再做出正確選擇．在做推理判斷題時(shí)不要以個人的主觀想象代替文章的事實(shí)，要根據(jù)文章事實(shí)進(jìn)行合乎邏輯的推理判斷．
