求助论坛大神一道OG17 SC题

sarading

求助各位大神一道OG 17的语法题目：




我选的是E，答案是C。各位大神能不能帮忙解释一下。

谢谢！

YanaSong

E的话，preventing的发出者是sound，不符合逻辑。

humingyi

这里涉及到一个生僻的知识点，在Manhattan里面有比较棒的讲解：
A few GMAT sentences use a sophisticated modifier called an Absolute Phrase. Absolute phrases are composed of a noun plus a noun modifler. These phrases do not have to modify what they touch; rather, they modify the main clause in some way.
Right: His head held high. Owen walked out of the store.
The absolute phrase His head held high is composed of a noun (His head) and a noun modifier (held high) that describes the noun. The phrase His head held high describes how Owen walked out of the store. Thus, this absolute phrase acts as a verb modifier. You might argue that the noun Owen is directly described by His head held high, especially since the pronoun His refers to Owen. However, you should note that His head held high is not an appositive noun modifler, We are not placing His head held high next to Owen to equate them. Moreover, we can easily move the modifier to the end of the sentence; we cannot do so with normal noun modifiers. We can also vary the phrase slightly by adding with.
Right: Owen walked out of the store, his head held high.
Right: Owen walked out of the store with his head held high.
Absolute Phrase有人翻译成独立主格。要注意以下几点：
1. 独立主格通常是一个名词+一个修饰语的形式出现，
2. 独立主格修饰的不是就近的名词，而是整个句子。

题目中： Sound can travel through water for enormous distances, its acoustic energy prevented from dissipating byboundaries in the ocean created by water layers of different temperatures and densities.
红色的部分都是独立主格：noun是its acoustic energy， 后面的prevented引导的一大串都是修饰"its acoustic energy"的modifier。
这道题最关键的解题思路是要理解语义：逗号后面的部分说的是声音的能量可以被***防止消散，这个fact使得声音可以在水中传播很远的距离。到底是独立主格还是普通的modifier，在你明白修饰对象之后，就很好分辨了。

fxxxfxxx

Sound 不能 prevent its energy from dissipating

咖啡印象

这题之前版上讨论得比较激烈，传送给露珠：http://forum.chasedream.com/thread-175239-1-1.html