楼主辛苦啦。
18题应该是不选comparison to
曼哈顿里说用compare to/with有两个原则:
1. the two things that are intended to be compared 这句湖里的BMI和body fat并不是天然形成对比的
2. no other comparison indicator
extent to which overweight and obesity 这个词组搭配是可以的 看了V44大神的分析后我查了一下 可以看这篇论文的用法 http://xueshu.baidu.com/s?wd=paperurib6a1f50d2d30dba16c05023dcdd7d174)&filter=sc_long_sign&sc_ks_para=q%3DImplications+of+Childhood+Overweight+and+Obesity+on+Learning+Behaviour+and+Classroom+Performance&tn=SE_baiduxueshu_c1gjeupa&ie=utf-8