求助：og10-205

iamyaoyao

205.The peaks of a mountain range,acting like rocks in a stream bed,produce ripples in the air flowing over them;the resulting flow pattern,with creats and troughs that remain stationary although the air that forms them is moving rapidly,are known as "standing waves."

B.crests and troughs that remain stationary although they are formed by rapid 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

正确答案是C,我很不理解og对E的解释，不知道到底问题在哪儿,还有对C的解释：正确地将although从句放入了关系从句的谓语中？

og:choice E uses the correct verb form,is,but it incorrectly introduces a dependent adverbial although clause into a prepositional phrase(with crests).choice 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)

hbsonlylove

although引导从句，必须要有主句才行啊。C中that指代crests and troughs，换句话说就是crests and troughs remain stationary although the air that forms them is moving rapidly. 而E是with stationary crests and troughs although they are formed by rapidly moving air，一个短语不能跟个从句

iamyaoyao

哦，对的哈，我没想到短语不能有从句。。非常感谢哈