The peaks of a mountain range, acting like rocks in a streambed, produce ripples in the air flowing over them; the resulting flow pattern, with crests and troughs that remain stationary although the air
that forms them is moving rapidly, are known as "standing waves."
A. crests and troughs that remain stationary although the air that forms them is moving rapidly, are
B. crests and troughs that remain stationary although they are formed by rapidly moving air, are
C. crests and troughs that remain stationary although the air that forms them is moving rapidly, is
D. stationary crests and troughs although the air that forms them is moving rapidly, are
E. stationary crests and troughs although they are formed by rapidly moving air, is 答案选C 我对C想没有疑问,就是想问下CE项中的crest and troughs that remian stationary和stationary crest and troughs是不是都是正确的表达还是E的这个表达也是不对的?因为OG中对E的错误只说了是因为although的错。。 |