阅读理解What will man be like in the future—in 5,000

阅读理解Next to Sir Andrew in the club-room sits

阅读理解Directions: In this part, there are six passages, each of which is followed by five questions. For eachquestion, there are four possible answers marked A, B, C, and D. Choose the best answer and markthe letter of your choice on the ANSWER SHEET.Passage ThreeHaving too much caffeine during pregnancy may impair baby liver development and increasethe risk of liver disease in adulthood, according to a study published in the Journal of Endocrinology.Pregnant rats given caffeine had offspring with lower birth weights, altered growth and stresshormone levels and impaired liver development. The study findings indicate that consumption ofcaffeine equivalent to 2-3 cups of coffee may alter stress and growth hormone levels in a mannerthat can impair growth and development, and increase the risk of liver disease in adulthood.Previous studies have indicated that prenatal caffeine intake of 300 mg/day or more in women,which is approximately 2 to 3cups coffee per day, can result in lower birth weights of their children.Animal studies have further suggested that prenatal caffeine consumption may have moredetrimental long-term effects on liver development with an increased susceptibility to non-alcoholicfatty liver disease, a debilitating condition normally associated with obesity and diabetes. However,the underlying link between prenatal caffeine exposure and impaired liver development remainspoorly understood. A better understanding of how caffeine mediates these effects could help preventthese health issues in people in the future.In this study, Prof Hui Wang and colleagues at Wuhan University in China, investigated theeffects of low (equivalent to 2-3 cups of coffee) and high doses (equivalent of 6-9 cups of coffee)caffeine, given to pregnant rats,on liver function and hormone levels of their offspring. Offspringexposed to prenatal caffeine had lower level of the liver hormone, insulin like growth factor(IGF-1),and higher levels of the stress hormone, corticosteroid at birth. However, liver development afterbirth showed a compensatory catch up phase, characterized by increased levels of IGF-1,which isimportant for growth.Dr. Yinxian Wen, study co-author, says,Our results indicate that prenatal caffeine causes anexcess of stress hormone activity in the mother, which inhibits IGF-1 activity for liver developmentbefore birth. However, compensatory mechanisms do occur after birth to accelerate growth andrestore normal liver function, as IGF-1 activity increases and stress hormone signalling decreases.The increased risk of fatty liver disease caused by prenatal caffeine exposure is most likely aconsequence of this enhanced, compensatory postnatal IGF-1 activity.These findings not only confirm that prenatal caffeine exposure leads to lower birth weight andimpaired liver development before birth but also expand our current understanding of the hormonalchanges underlying these changes and suggest the potential mechanism for increased risk of liverdisease in the future. However, these animal findings need to be confirmed in humans.Dr. Wen comments,Our work suggests that prenatal caffeine is not good for babies andalthough these findings still need to be confirmed in people, I would recommend that women avoidcaffeine during pregnancy.

阅读理解The years between 1870 and 1895 brought

阅读理解In 1987, H. I. V/AIDS joined a list of

阅读理解For laymen ethnology is probably the most

阅读理解It didn't happen overnight. The problem of

阅读理解Depending on your age and memory, it was a

阅读理解Married people live "happily ever after" in

阅读理解The history of responses to the work of the

阅读理解There is no denying that students should

阅读理解On an average of six times a day, a doctor

阅读理解The next time the men were taken up onto the

阅读理解Web browsers! Interactive software! There's

阅读理解For me, scientific knowledge is divided into

完形填空Ironically, the intellectual tools currently

完形填空By 1830 the former Spanish and Portuguese

完形填空In the past few decades, remarkable findings

完形填空At least since the Industrial Revolution,

完形填空The translator must have an excellent,