feifei-114

mariezhu

114. The number of North American children who are obese-that is, who have more body fat than do 85 percent of North American children their age---is steadily increasing, according to four major studies conducted over the past 15 years.

If the finding reported above is correct, it can be properly concluded that

(A) when four majors studies all produce similar results, those studies must be accurate

(B) North American children have been progressively less physically active over the past 15 years

(C) the number of North American children who are not obese increased over the past 15 years

(D) over the past 15 years, the number of North American children who are underweight has declined

(E) the incidence of obesity in North American children tends to increase as the children grow older

答案是C，不明白，怎么推出children who are not obese的人数多了?

ssss

胖人的定义是比85％的人都要胖，即人群中15％是胖人，85％的人不胖。


占总比例15％的胖人的人数增加了=>总人数增加了＝》占85％的不胖的人数也增加了

mariezhu

明白了，谢...