OG SC90 Help~~~

perain

90. 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
Agreement
The subject of the second independent clause is the resulting flow pattern; this
singular subject requires the singular verb is known, not the plural verb are
known. While the long descriptive construction between the subject and verb
may make it difficult to see this relationship, notice that the modifying phrase is
set off with commas. The use of the active voice in the verbs of the subordinate
clauses provides greater clarity of meaning.
A The plural verb does not agree with the singular subject
B The plural verb does not agree with the singular subject; the subordinate
clause in the passive voice following although is awkward and unclear
C Correct. In this sentence, the singular verb is known agrees with the subject
the resulting flow pattern.
D The plural verb does not agree with the singular subject; awkward and
confusing construction
E The clause following although is awkward and Unclear
The correct answer is C.



正确选项是C，可我觉得E也对，但是答案是说E是awkward and unclear，还是不太明白~~求助各位，感谢！！

clumsy123

说说我滴看法~有两点
1、把that remain  stationary换成stationary并且提前，意思不太一样了。原句说的是“一直是静止的。。。”，而E说的是“静止的。。。”，意思是不是有差异？
2、GMAT语法是尽量不要用被动的，因为会显得很奇怪，而且用了被动句子意思有变化。原句强调的是the air。。is moving。而E则说they are formed by。。air，句子重心变了~

Lusiazh1989

说说我滴看法~有两点
1、把that remain  stationary换成stationary并且提前，意思不太一样了。原句说的是“一直是静止的。。。”，而E说的是“静止的。。。”，意思是不是有差异？
2、GMAT语法是尽量不要用被动的，因为会显得很奇怪，而且用了被动句子意思有变化。原句强调的是the air。。is moving。而E则说they are formed by。。air，句子重心变了~

-- by 会员 clumsy123 (2011/4/20 15:58:20)

正在纠结此题，看到这个解释好像明白了。只是做题的时候觉得C真的很罗嗦，就想还是E比较好。
最优项这个问题让我很困绕。。