请教OG-205

joywzy

205. 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."

crests and troughs that remain stationary although the air that forms them is moving rapidly, are
crests and troughs that remain stationary although they are formed by rapidly moving air, are
crests and troughs that remain stationary although the air that forms them is moving rapidly, is
stationary crests and troughs although the air that forms them is moving rapidly, are
stationary crests and troughs although they are formed by rapidly moving air, is
The main challenge in this sentence is to observe the agreement of subject and verb (the resulting flow pattern... is known...) despite the distraction of a complex intervening structure containing several plural elements (with crests and troughs...). Choices A, B, and D can, therefore, be eliminated because they use an incorrect plural verb form, are. Choice E uses the correct verb form, is, but it incorrectly introduces a dependent adverbial although clause into a prepositional phrase (with crests ...). Choice D also makes this error. Such dependent clauses can only occur in the predicates of full clauses. C, the best choice, uses the correct verb form, is, and correctly puts the although clause inside the predicate of the relative clause (that... rapidly).

答案：C，我想请教C和E的差别，尤其是：Choice E uses the correct verb form, is, but it incorrectly introduces a dependent adverbial although clause into a prepositional phrase (with crests ...)

我怎么也理解不来？能帮助讲讲吗？谢谢。

1stzhang

with后面接的是短语，但是E中with+.....+although从句，这是绝对不可以的。应为although引导的是让步状语从句，不可以修饰短语。