标题: 求助大家，看看这道逻辑题选什么？ [打印本页] 作者: cocostea 时间: 2011-6-8 06:50 标题: 求助大家，看看这道逻辑题选什么？ The number of North American children who are obese – that is, whohave more body fat than do 85 percent of North American children their age – issteadily increasing, according to four major studies conducted over the past 15years. Ifthe finding reported above is correct, it can be properly concluded that: ? A) when four major studies all produce similar results, thosestudies must be accurate. ? B) North American children have been progressively less active overthe past 15 years. ? C) the number of North American children who are not obese increasedover the past 15 years.
? D) over the past 15 years, the number of North American children whoare underweight has declined. ? E) the incidence of obesity in North American children tends toincrease as the children grow older.作者: connie飘着 时间: 2011-6-8 07:15
我觉得选a吧。答案是什么呢？作者: cocostea 时间: 2011-6-8 07:31
答案是C，弄不懂为啥！有同学看出来原因的吗？作者: camelo777 时间: 2011-6-8 08:43
注意理解题目，题目对于obese的定义是who have more body fat than do 85 percent of North American children their age，也就是说肥胖的定义是比85%的孩子要胖，那么既然肥胖的比率在上升，说明总的孩子的比率在上升，因此抛去肥胖的孩子，不胖的孩子数量肯定也在增加，因此C正确作者: sdcar2010 时间: 2011-6-8 09:49
LS almost got it right.
Number of overweighted children = (100%-85%)*Number of all children
So if Number of overweighted children is up, so is Number of all children. But the overweight rate is always 15%.
Then Number of Not-obese children = 85% * Number of all children. If Number of all children is up, so is the Number of not-obese children.作者: cocostea 时间: 2011-6-9 05:49
it makes sense, thank you作者: connie飘着 时间: 2011-6-9 07:51
o, i c. actuall i just know a is irrelevant. now i know, tks