9．Nowadays the U．S．students are sleepy in school because they spend too much time texting，playing video games，watching TV and using the media in other ways．
"Heavy media use interferes with sleep by reducing sleep duration，making it harder to fall asleep，and lowering sleep quality，"Meilan Zhang，an assistant professor at the University of Texas at El Paso，wrote in her research review in the journal，Sleep Medicine．
But the relationship between youth's media use and sleep is not so simple，said Michael Gradisar，who authored both that review and the Sleep Medicine meta-analysis．"Technology use is the new evidence when we are trying to answer‘Why are school-age children sleeping less？'"said Mr．Gradisar，an associate professor of psychology at Flinders University in Adelaide，Australia．
There may be safe limits to technology use，Mr．Gradisar stated．For instance，recent research results indicate that using a bright screen for an hour before bed or even playing violent video games for less than that will not necessarily interfere with teenagers'sleep，he wrote．
But longer periods of usage can be harmful to sleep，Mr．Gradisar added．Rather than delaying school start times，he said，the first step should be educating parents about limiting the hours that their children are using technology before bed，and enforcing a consistent bedtime．
Early school start times are also commonly blamed for students'sleepiness，especially for adolescents．Secondary schools around the nation and the world have been delaying start times，often with positive results．
Mr．Minnich of the TIMSS and PIRLS International Study Center hesitated to put blame to any particular factor．But he did think that cost-saving measures to consolidate（合并）bus routes might help explain U．S．students'sleepiness．
"For those children who board the bus first，they must get up earlier，may end up sleeping on the way to school，and may end up arriving at school sleepy．"he said．
13．Which of the following may be the good way to help kids sleep better？C
A．Parents should be well educated．
B．Technology is forbidden at home．
C．Their playing time must be limited．
D．They are allowed to go to school early．
14．What would be the factors that cause kids sleep troubles according to the textC
a．Using the media．
b．Having breakfast．
c．Catching the bus．
d．The school timetable．
e．Doing too much homework．
A．a，d，e B．b，c，d
C．a，c，d D．b，d，e
15．Which of the following may be the best title for the text？D
A．Kids benefit a lot from technology．
B．Several sleep troubles appear at school．
C．Some tips can help kids sleep well．
D．Several factors affect kids'sleep．
分析 本文屬于生活類閱讀，現(xiàn)在美國的孩子由于過度使用媒體設備，睡眠時間較短，睡眠的質量也較差．作者在文章中分析了這一現(xiàn)象的原因．
解答 13．C．推理判斷題．根據(jù)文章第五段第一句But longer periods of usage can be harmful to sleep，Mr．Gradisar added．可知長時間使用媒體設備會對學生的睡眠有害．所以本周孩子取得良好睡眠的最好方法就是限制使用媒體設備的時長．故C正確．
14．C．細節(jié)理解題．根據(jù)最后一段"For those children who board the bus first，they must get up earlier，may end up sleeping on the way to school，and may end up arriving at school sleepy可知使用媒體，趕上公共汽車，學校時刻表會導致孩子睡眠困難；故選C．
15．D．標題概括題．根據(jù)文章第一段Nowadays the U．S．students are sleepy in school because they spend too much time texting，playing video games，watching TV and using the media in other ways．可知可知本文告訴我們美國學生在學校很困，主要是因為他們把太多的時間花在了發(fā)信息，玩游戲，看電視以及用其他方法玩媒體上．接著就分析了這些媒體設備影響孩子們睡眠的情況．故D項正確．
點評 考察學生的細節(jié)理解和推理判斷能力，做細節(jié)理解題時一定要找到文章中的原句，和題干進行比較，再做出正確的選擇．在做推理判斷題不要以個人的主觀想象代替文章的事實，要根據(jù)文章事實進行合乎邏輯的推理判斷．
