OG13上一个语法点的疑问？

言多必湿7

OG13-语法-13题

There are several ways to build solid walls using just mud or clay, but the most extensively used method has been the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid in the wall in mud mortar.

　　(A) the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid

　　(B) forming the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them

　　(C) having bricks formed from mud or clay, and, after some preliminary air drying or sun drying, they were laid

　　(D) to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them

　　(E) that bricks were formed from mud or clay, which, after some preliminary air drying or sun drying, were laid

我知道通过平行结构的考点与时态。选D是最好的。但是将D选项代入原文，发现是：but the most extensively used method has been to form the mud or clay。这里出现了一个has been to do sth ，英语中的完成时不能这么用啊。那D就是语法有问题啊。跪求大神解答！！！

SansanHe

the method/way is to do…用来表method的内容

言多必湿7

SansanHe 发表于 2015-8-25 09:07
the method/way is to do…用来表method的内容

就是说是这个the method is to do sth的完成时（the method has been to do sth ）的形式吧? 第一次见到这一种完成时态