6．PALO AITO，California-"Switching off the television may help prevent children from getting fatter--even if they do not change their diet or increase the amount they exercise，"US researchers said last week．
A study of 192 third and fourth grades students，generally aged eight and nine，found that children who cut the number of hours spent watching television gained nearly two pounds （0.91kg ） less over a one-year period than those who did not change their television diet．
"The findings are important because they show that weight loss can only be the result of a reduction in television viewing and not any other activity，"said Thomas Robinson，a pediatrician （儿科专家）at Stanford University．
"American children spend an average of more than four hours per day watching television and videos，and rates of childhood being very fat have doubled over the past 20 years，"Robinson said．
In the study，presented this week to the Pediatric Academic Societies'annual meeting in San Francisco，the researchers persuaded about 100 of the students to reduce their television viewing by one-quarter to one-third．
Children watching fewer hours of television showed a significantly smaller increase in waist size and had less body fat than other students who continue their normal television viewing，even though neither group ate a special diet nor took part in any extra exercise．
"One explanation for the weight loss could be the children unstuck to the television may simply have been moving around and burning off calories，"Robinson said．
"Another reason might be due to eating fewer meals in front of the television．Some studies have suggested that eating in front of the TV encourages people to eat more，"Robinson added．
39．What do the first two paragraphs imply？D
A．Children in the US are tired of watching TV．
B．Watching TV can help children to loose weight．
C．Younger children watch more TV than older ones．
D．More TV viewing is harmful to children's health．
40．In average，the time American children spend watching TVA．
A．is more than four hours a day
B．is less than four hours a day
C．has doubled in the last twenty years
D．is more than doing any other things
41．The researchers made sure the students didn't change their diet in order toD．
A．keep them from getting too heavy
B．enable them to do more exercises
C．reduce their time watching TV
D．make their findings more believable
42．According to the passage，why can watching TV increase kids'weight？A
A．They usually eat more while watching TV．
B．They change their diet while watching TV．
C．They burn off more calories while watching TV．
D．They don't want to take exercise while watching TV．
分析 本文主要讲的是关掉电视有助于防止儿童发胖的问题，并进行大量实验进行验证，美国儿童看电视时间太长，文章建议减少孩子看电视的时间，并分析原因．
解答 39．D．细节理解题．根据前两段中"Switching off the television may help prevent children from getting fatter"以及"found that children who cut the number of hours spent watching television gained nearly two pounds"可知，这些都是看电视的危害．故选D．
40．A．细节理解题．根据第四段第一行"American children spend an average of more than four hours per day watching television and videos or playing video games．"可知．故选A．
41．D．细节理解题．根据文中第六段中叙述可知，不改变其饮食是为了控制变量，改变的只是看电视的时间长短，使实验更有说服力．故选D．
42．A．细节理解题．根据文中最后一句话"eating in front of the TV encourages people to eat more"可知．故选A．
点评 本文是新闻报道类阅读理解文章，阅读此类文章主要是要了解：
①新闻报道了什么事件；②事件是因为什么而发生的，相关背景如何；③文段中指出的事件发生过程中的突出细节是 什么；④事件造成的后果是什么；⑤事件的本质是什么，透过事件的表面现象，我们看到了什么社会问题．通过这样的梳理，我们就可以把新闻的脉络理清楚．这类材料命题点往往落在事实细节上
