12．In a time when a dangerous number of people are overweight，many people seem to have forgotten the most important way to keep healthy and slim---exercise．And as a new study carried out on mice in the lab has shown，exercise done early in life can rward you in your adult years．
A team of researchers at the University of California studied the effects of early exercise on adult physical activity，body mass and eating．They found that early-age exercise in mice has positive effects on adult levels of voluntary exercise in addition to reducing body mass．
"These results may have an effect on the importance of regular physical education in elementary and middle schools，"said Theodore Garland，a professor of biology，who led the research project．"If kids exercise regularly through their school years，then they may be more likely to exercise as adults，which could have far-reaching poitive effects on human health and well-being．"
Although the positive effects of early-life exercise lasted for only one week，it is important to note that one week in the life of a mouse is the same as about nine months for humans．"Our results suggest that any positive effects of early-life exercise on adult eercise will need to be kept up if they are to be long-lasting．"
His team of researchers found，too，that all mice that had access to early exercise were lighter in weight than non-exercised mice．
Garland explained that，in general，exercise will stimulate appetite sooner or later．However，it is possible that certain types of exercise，done for certain periods of time or at certain light levels，might not stimulate appetite much，if at all，at least in some individuals．
"If we could understand what sorts of exercise these might be，then we might be able to tailor exercise recommendations in a way that would bring the benefits of exercise without increase in appetite，leading to a better chance of weight loss，"he said．
28．How long do the positive effects of early-life exercise last for a mouse？B
A．One day B．One week C．One month D．Nine months
29． Which of the following statements is TRUE according to the article？A
A．More study is needed to better understand the effects of different types of exercise．
B．Early-life exercise has life-long positive effects on people
C．Kids should be encouraged to o exercise as early as possible to ensure physical health．
D．The new study on mice mainly focused on how exercise affects appetite．
30．The underlined word"stimulate"in the last but one paragraph is closest in meaning toB．
A．decline B．improve C．vary D．harm
31．What is the article mainly about？D
A．New ways to fight against being overweight．
B．The positive effects of mice
C．The possible risks of doing exercise
D．The positive effects of early-life exercise．
分析 本文屬于說明文閱讀，作者通過這篇文章向我們介紹了在生命的早期鍛煉可以幫助你在成年后獲得健康的生活，并通過用小白鼠實驗證明了這個觀點，因此作者提倡我們多進行鍛煉，保持自己身體的健康．
解答 28．B 細(xì)節(jié)理解題，根據(jù)第四段Although the positive effects of early-life exercise lasted for only one week，it is important to note that one week in the life of a mouse is the same as about nine months for humans．雖然早期的正面效果只能持續(xù)一個星期，可知小老鼠的早期鍛煉能持續(xù)一個星期，故選B．
29．A 推斷判斷題．根據(jù)第七段："If we could understand what sorts of exercise these might be，then we might be able to tailor exercise recommendations in a way that would bring the benefits of exercise without increase in appetite，leading to a better chance of weight loss，"如果我們能研究出這些鍛煉形式都有哪些，或許我們可以給人們量身定做一些鍛煉建議，這樣可以帶來如期的鍛煉效果而不會增加胃口，從而達(dá)到減肥的效果，可知我們的研究還沒有到位，故選A．
30．B 詞義猜測題，根據(jù)第六段However，it is possible that certain types of exercise，done for certain periods of time or at certain light levels，might not stimulate appetite much，if at all，at least in some individuals．可知有可能一些鍛煉形式對某些個體來說不會那么刺激人的胃口，故選B．
31．D 主旨大意題，通讀全文可知本文主要向我們介紹了早期生活鍛煉的積極影響，故選D．
點評 考查學(xué)生的細(xì)節(jié)理解和推理判斷能力．做細(xì)節(jié)理解題時一定要找到文章中的原句，和題干進行比較，再做出正確選擇．在做推理判斷題時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．
