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(肠).
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(内毒素) 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 本文属于说明文阅读,作者通过这篇文章向我们介绍了一项新的关于人类肥胖的原因的调查研究,科学家们发现人类肥胖与细菌有关,肠道菌群可能会导致人类肥胖.
解答 36.D 细节理解题,根据第一段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.可知我们在冬天暴饮暴食之后严格控制饮食是因为我们不想看起来很胖,故选D.
37.A 细节理解题,根据第四段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.可知从赵丽萍的研究中我们可以知道一种特殊的细菌与人们的肥胖有关,故选A.
38.C 推理判断题,根据第七段In 2004,American microbiologist Jeffrey Gordon and his colleagues discovered a general link between obesity and gut microbiota in mice以及最后三段科学家们的研究可以知道老鼠的超重与人类的超重都与肠道菌群有关,故选C.
39.B 推理判断题,根据最后三段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.可知病人是在肠道菌群数量减少之后减掉了51.4kg的体重,故选B.
40.C 主旨大意题,通读全文可知本文作者主要向我们介绍了一项有关人类肥胖的医学发现,故选C.
点评 考查学生的细节理解和推理判断能力.做细节理解题时一定要找到文章中的原句,和题干进行比较,再做出正确选择.在做推理判断题时不要以个人的主观想象代替文章的事实,要根据文章事实进行合乎逻辑的推理判断.