为什么不能用act like a buffer as as to absorb

discard2

In a plan to stop the erosion of East Coast beaches,the Army proposed building parallel to the shore a breakwater of rocks that would rise 6 feet above the waterline and （act as a buffer ,absorbing ）the energy.

为什么不能用act like a buffer as as to absorb?我认为absorb和act的主语一样的，都是rock ,为什么不行？

brigittew

act as,作为，象。。。一样（就是）
act like, 象。。。一样（象而不是）
这是中学的解释，不太全面，但够用
anyway, here, act as a buffer, actually, when there is sea wave, the breadwater of rocks is a buffer, not like..

primefang

act as 是作为, act like是"象" 意思上是有区别的