although的存在是为了表达转折的含义,从句意上看是stationary和moving rapidly的转折对比
先看正确选项,连接的是that remain stationary 和the air is moving rapidly,结构、含义上都非常对称。
再看正确选项E里面although连接的却是crests and troughs和they are formed by rapidly moving air,可以发现crests and troughts与它们怎么形成的无法形成一个"转折"。能形成转折的是crests and troughts的stationary和air的moving rapidly.
-- by 会员 miaomiao5973 (2011/5/30 0:53:11)