2．For years we have been dieting strictly after the year-end overeating，afraid that when summer．comes，the bigger size we have accumulated will betray how we ate．Now scientists say，it's a little bug that causes obesity（肥胖）．
As the holiday season with its abundant feasting arrives，millions of food lovers are keeping an eye on their figures．But scientists have found that weight gain is not about too much Christmas turkey or hot chocolates，but some bacteria in your guts（腸）．
Chinese scientists recently discovered a type ofbacteria in guts that may be to blame for obesity．
A research team led by Zhao Liping，a professor in Shanghai，has identified a precise link between a particular kind ofbacteria and unusual weight gain．
"The endotoxin（內毒素） released by the bacterium can activate（激活） a gene that helps produce fat．And it also deactivates a gene that consumes fat，"Zhao says．
Scientists have long believed that microscopic organisms in the gut，microbiota，may play a very important role in weight gain，but they had never been able to prove it．
In 2004，American microbiologist Jeffrey Gordon and his colleagues discovered a general link between obesity and gut microbiota in mice．
While a link was believed to exist，proving it was another matter．
"The list of diseases that they may play a role in is just growing and growing，"says Lita Proctor，director of the US National Institutes of Health．"But the problem is that we're only able to look at associations and aren't yet able to conduct cause-and-effect studies．"
In the clinical study，researchers found a growth of too much endotoxin-producing bacteria，leading t0 35percent ofthe gut bacteria，in an obese patient whose initial weight was 175kg．
Based on this information，researchers tried to cure the patient by feeding him a specialized nutritional liquid food to decrease the bacteria in his guts to ignorable amounts．
After 23 weeks，the patient lost 51.4kg，with his fatty liver disease having almost disappeared．
36．We diet strictly after the year-end overeating becauseD．
A．we won't betray ourselves
B．we eat too much turkey
C．there are bacteria in our guts
D．we don't want to look fat
37．What can be learned from Zhao's research？A
A．Obesity is related to a kind of bacteria．
B．Healthy diet helps reduce your fat．
C．Chocolate doesn't cause weight gain．
D．Too much food leads to overweight．
38．Which of the following statements is TRUE？C
A．Scientists didn't try to find out the cause of overweight．
B．There is a link between mice's overweight and human's．
C．Lita proved the link between bacteria and weight gain．
D．Scientists found bacteria may be related to many diseases．
39．The patient finally lost 51.4kg of his weight afterB．
A.35percent of his gut bacteria were killed
B．the amount of gut bacteria was decreased
C．he had a special kind ofoperation
D．his fatty liver had disappeared
40．What does the passage mainly talk about？C
A．People's eating habits．
B．Healthy lifestyles．
C．A medical discovery．
D．The consequence of obesity．
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一項新的關于人類肥胖的原因的調查研究，科學家們發(fā)現(xiàn)人類肥胖與細菌有關，腸道菌群可能會導致人類肥胖．
解答 36．D 細節(jié)理解題，根據第一段For years we have been dieting strictly after the year-end overeating，afraid that when summer．comes，the bigger size we have accumulated will betray how we ate．可知我們在冬天暴飲暴食之后嚴格控制飲食是因為我們不想看起來很胖，故選D．
37．A 細節(jié)理解題，根據第四段A research team led by Zhao Liping，a professor in Shanghai，has identified a precise link between a particular kind ofbacteria and unusual weight gain．可知從趙麗萍的研究中我們可以知道一種特殊的細菌與人們的肥胖有關，故選A．
38．C 推理判斷題，根據第七段In 2004，American microbiologist Jeffrey Gordon and his colleagues discovered a general link between obesity and gut microbiota in mice以及最后三段科學家們的研究可以知道老鼠的超重與人類的超重都與腸道菌群有關，故選C．
39．B 推理判斷題，根據最后三段In the clinical study，researchers found a growth of too much endotoxin-producing bacteria，leading t0 35percent ofthe gut bacteria，in an obese patient whose initial weight was 175kg．Based on this information，researchers tried to cure the patient by feeding him a specialized nutritional liquid food to decrease the bacteria in his guts to ignorable amounts．After 23 weeks，the patient lost 51.4kg，with his fatty liver disease having almost disappeared．可知病人是在腸道菌群數量減少之后減掉了51.4kg的體重，故選B．
40．C 主旨大意題，通讀全文可知本文作者主要向我們介紹了一項有關人類肥胖的醫(yī)學發(fā)現(xiàn)，故選C．
點評 考查學生的細節(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，要根據文章事實進行合乎邏輯的推理判斷．
