[解析]
(1)A.细节理解题。根据第三段Scientists concluded that weight gain seemed to be influenced by genetic factors.They also believe they have now identified the genes that may cause this tendency. (科学家得出结论,体重增加似乎受到遗传因素的影响。他们还认为,他们现在已经确定了可能导致这种趋势的基因。)可知,体重增加是受到了遗传因素的影响。故推知有些人容易增加体重是因为他们的基因造成这种趋势。故选A。
(2)B.推理判断题。根据第二段Scientists say that when some people eat,their bodies will naturally store the excess energy from food as fat.These people gain weight if they eat more than they need each day.Meanwhile,other people eat more than they need but their bodies are able to "burn off " the extra food without making fat,so they rarely have weight problems. (科学家说,当有些人进食时,他们的身体会自然地将食物中多余的能量储存为脂肪。如果这些人每天吃得比他们需要的多,他们就会增加体重。与此同时,其他人吃得比他们需要的多,但他们的身体能够在不产生脂肪的情况下燃烧掉多余的食物,所以他们很少出现体重问题。)及第三段To show that this is true,scientists have experimented on laboratory mice. (为了证明这是真的,科学家们在实验室小鼠身上进行了实验。)可知,科学家为了寻找人们增加体重的原因,证明自己的判断是正确的,做了这个实验。故选B。
(3)B.细节理解题。根据第四段In the United States,over seventy percent of the population have weight problems.This means they are at risk of illness such as high blood pressure and heart disease. (在美国,超过百分之七十的人口有体重问题。这意味着他们有患高血压和心脏病等疾病的风险。)可知,体重问题会导致高血压。故选B。
(4)C.目的意图题。根据最后一段Therefore,despite this breakthrough in the study of weight﹣loss drugs,scientists and health professionals all agree that currently the best way to control weight gain is to have a healthy,balanced diet and an active lifestyle with daily exercise.This will not only help people avoid becoming overweight,but also help them stay healthy and energetic. (因此,尽管减肥药物的研究取得了突破,但科学家和卫生专业人员都同意目前控制体重增加的最佳方法是拥有健康,均衡的饮食和积极的生活方式和日常锻炼。这不仅可以帮助人们避免超重,还可以帮助他们保持健康和精力充沛。)可知,科学家们认为均衡的饮食和积极的生活方式和日常锻炼是保持健康的最佳方式。由此推知,最后一段的目的是建议我们养成健康的生活方式。故选C。