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
题目分析：划线内外用and形成了一个并列关系，act这个词应该和划线外的rise对应，不能用acting，干掉D和E。act和absorb发起者没变，不需要加it，干掉A。absorb这个动作和act发起在意思上没有先后关系，不是先act之后在absorb的，干掉B。选C。
