请教平行结构

OG上面2个题的正确答案：

1。The Baldrick Manufacturing Company has for several years followed a policy aimed at decreasing operating costs and improving the efficiency of it`s distribution system

既然题目的要点是平行结构，为什么不是aimed at decreasing operating costs and  at improving

2.In contrast to large stell plants that take iron ore through all the steps needs to produce several different kinds of steel, small mills, by processing steel scrap in to a specialized group of products, have been able to put capital into new technology and remain economically viable.

同理，为什么不是to put and to remain。

是否可以省略，多谢指教