feifei 114 --help, it makes me crazy

dhhgh11

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 major 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

the answer is C, but I really have no idea about this question

kuuiytt

没看过费费逻辑，说点看法，不对的话别见笑。

我觉得题干里面their age前面是不是少了at啊，有点读不通，但不妨碍理解意思。

这道题有2个要素：（1）北美肥胖儿正在稳步增长（2）肥胖儿的标准是比85％的同龄人胖。

其实这个标准很荒谬，按它来说，北美就只有永远只有15％的胖孩子，当然这里不用考虑它的问题。但是根据这个标准，我们知道：北美胖童人数＝北美全体儿童人数×15％；北美不胖儿童人数＝北美全体儿童人数×85％，所以，如果胖童增加，说明儿童总数增加，儿童总数增加，则不胖儿童的人数增加。