17．If you are sitting，please stand up．Move your legs．Touch your toes if you can．Do anythin g but sit．New research shows that if you cut down on the time you spend sitting，you might live longer．Sitting less than three hours a day might extend your life by two years．Cutting television time to less than two hours a day can add one point four years to life．
The human body is designed to move．The fact is just the opposite．Modern lifestyles and office jobs rarely give us the chance to move around．We sit while we're eating； we sit in the car； we sit while we are watching TV．And most of us sit for many hours at work．Sitting is something we do all the time．On average，Americans sit for four and a half to five hours a day．But that does not make sitting good for us．
Though you may exercise often，that does not mean you can sit for the rest of your waking hours．We can't throw away physical activity．It is extremely important．Even if you exercise for 30 minutes a day，what goes on in the other 23 and a half hours a day is also very important．
Changes are coming to some offices，especially in the design of desks．A"standing desk"lets people stand while they work．Another new design is called the"treadmill desk"．It is an exercise machine that lets you walk slowly in one place．Even some U．S．schools begin to experiment with desks that are part bicycle to keep children moving．
Many companies may not buy a standing desk for everybody．However，they may get five standing desks or a treadmill desk for their employees and put them in a certain place where people can go for an hour a day to answer their emails or talk on the phone．Experts suggest some other activities：take a walk at lunchtime； walk to the offices and talk directly instead of emailing colleagues．All these activities may help you live longer．
28．Why should people stand up according to the new research？C
A．They should touch their toes．
B．Standing more can cure some diseases．
C．Sitting less does people good and may help people live longer．
D．They spend too much time watching TV．
29．What can we learn about sitting？B
A．Sitting is the best position for the body．
B．People usually have to sit for a long time nowadays．
C．The more people sit，the better they will be．
D．Americans sit longer every day than people in other countries．
30．What does the underlined word"It"in Paragraph 3 refer to？D
A．The walking hour
B．Sitting
C．Standing．
D．Exercising
31．Which of the following is TRUE according to the passage？A
A．The new design of desks can help people sit less．
B．The"treadmill desk"is used by people to run．
C．It's better for school students to use standing desks．
D．It's necessary for companies to offer a sitting desk to every employees．
分析 長時間坐對人們的健康有很大的危害，而現(xiàn)代生活方式讓人們長時間坐著．為了改變這一情況，人們發(fā)明了新式的椅子，這種椅子可以讓人們站著工作，以提高人們的健康水平．
解答 28．C．推理判斷題．根據(jù)第一段后兩句Sitting less than three hours a day might extend your life by two years．Cutting television time to less than two hours a day can add one point four years to life．可知每天坐的時間較少對我們的健康很有好處，可以延長我們的生命．所以作者建議人們平時要少坐多站．故C項正確．
29．B．細(xì)節(jié)理解題．根據(jù)第二段第三句Modern lifestyles and office jobs rarely give us the chance to movearound．可知現(xiàn)代的生活方式給予我們四處走動的機會很少．也就是說現(xiàn)在的人通常要坐很長時間．故B項正確．
30．D．詞義猜測題．根據(jù)本段前兩句Though you may exercise often，that does not mean you can sit for therest of your waking hours．We can't throw away physical activity．可知即使你經(jīng)常鍛煉，也并不意味著你就可以坐很長時間．鍛煉對我們很重要，但是鍛煉之外的時間也很很重要．所以本句中的it就是指"exercising"，故D項正確．
31．A．細(xì)節(jié)理解題．根據(jù)第三段A"standing desk"lets people stand while they work．Another new design is called the"treadmill desk"可知課桌新設(shè)計可以幫助人們少坐；故選A．
點評 考察學(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．
