老题仍旧有疑惑的地方

alexcui31707

[size=1em]Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy as a result ofboundaries in the ocean created by water layers of different [size=1em]temperatures and densities. [size=1em]A.      prevented from dissipating its acoustic energy as a result of [size=1em]B.  prevented from having its acoustic energy dissipated by [size=1em]C.  its acoustic energy prevented from dissipating by [size=1em]D.  its acoustic energy prevented from being dissipated as a result of [size=1em]E   preventing its acoustic energy from dissipating by 在这个里面对于C这个选项，我的问题是dissipating 从意思上看，是能量呗boundaries 消散不是应该是being dissipated 。这里不用being 结构。是不是因为BY的存在呢。。。求大虾来解答小弟的疑惑

YOYOwhatsup

因为dissipate是不及物动词，所以不能用被动形式，by是用来修饰prevented的，这是一道独立主格结构的问题