V-ing独立结构表伴随和结果外，还能修饰逗号前的名词么

kevin405hu

请问absorbing...and protecting...在句子中做什么成分，逻辑主语是谁？
一般只知道v-ing独立结构，表伴随或者结果，逻辑主语是主句的主语，但这里好像不是修饰the Army Corps...更像是修饰紧挨着的a buffer.这是什么用法啊？请赐教！

65. In a plan to stop the erosion of East Coast beaches,
the Army Corps of Engineers proposed building
parallel to shore a breakwater of rocks that would rise
six feet above the waterline and act as a buffer, so
that it absorbs the energy of crashing waves and
protecting the beaches.
(A) act as a buffer, so that it absorbs
(B) act like a buffer so as to absorb
(C) act as a buffer, absorbing
(D) acting as a buffer, absorbing
(E) acting like a buffer, absorb

frank73110

The first portion before the comma is the independent clause followed by an absolute phrase. An absolute phrase does not modify any word in particular: it modifies the whole sentence that either precedes or follows it. Therefore, it is not the Army Corps of Engineers which absorb anything. Instead, it is the fact what they proposed which absorb and protect the beach. hope u can understand.
Rgrds
Frank