Feifei-114

windweed

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, 我不理解. 我理解是题目中85 percent of North American children中包括The number of North American children who are obese. 但是这其中的绝对,相对和BASE 的关系把我弄糊涂了. 请教你的指点.

cranberry

好象全部狒狒的题目是有一群牛人的解释的

windweed

我知道他们给了9题解释的样本. 不知道其他的是不是已经出来了. 试图搜寻过,没有结果. 不过这题我一直都没FIGURE OUT.

cranberry

应该有全部的

lawyer_1

原文讲OBESE的定义是比85%的人胖。即15%是胖子。即不管胖瘦，反正15%是胖子，85%是不胖的。所以胖子的人多了，当然不胖的人也多了。因为胖和不胖是相对概念，两类加起来就是全部，比例又固定，所以一类多了，另一类也跟着多。

windweed

以下是引用lawyer_1在2004-11-14 20:22:00的发言：

原文讲OBESE的定义是比85%的人胖。即15%是胖子。即不管胖瘦，反正15%是胖子，85%是不胖的。所以胖子的人多了，当然不胖的人也多了。因为胖和不胖是相对概念，两类加起来就是全部，比例又固定，所以一类多了，另一类也跟着多。

你这么一解释,一下就明白了. 部分增加->它的BASE 增加->以BASE 为基础的其他%也就跟着增长. 太佩服了.非常感谢.

fighting127

终于清楚了 比例是固定的

fiona_hq

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