请教OG11的90题，为何E不对？

elle08

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

我觉得E的表达更为简洁阿，为什么E不对呢？

charlie6989

E they 指代不清 , 且被动语态
crests and troughs that remain stationary 和 stationary crests and troughs
两者表达意思不同

elle08

stationary crests and troughs是否会造成误解认为只有crests是stationary的？

但是，这里的they指代的不就是crests和troughs吗？和C的them指代是相同的啊？

烦请帮忙进一步解惑呢？ 

charlie6989

这两种表达stationary (crests) and troughs , or stationary ( crests and troughs)
都和 crests and troughs that remain stationary 表达是不同意思 注意 有remain这个动作
并非 crests and troughs that is stationary
they 可指 crests or troughs or (crests and troughs)
最好的答案就是避免歧义

Rsimon

C.although the air that forms them is moving rapidly

E. although they are formed by rapidly moving air

我觉得这两句话表达的意思不同。C更清晰得忠实原文意思，表达了the air的属性。

elle08

Got it!

谢谢charlie！