og12 sc11

zhangfan89

11.   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
Parallelism; Verb form  
The purpose of the sentence is to describe the historically most popular method of building walls. The first clause announces this topic and the second clause describes the particular method. The clearest, most efficient way to accomplish these two pieces of business is to use a parallel structure. The ways to build in the first clause is narrowed to the single way to form and to lay in the second clause. There is no need to alternate the verb phrases between active and passive voice or to shift tenses.
为什么to way 决定了to form和to lay？
求解~~

zhangfan89

希望NN解答~

jili_111

我不是NN，个人拙见是：but是parallel maker，所以 way to build 要和but后的method to form平行，而to form要和and后面的to laid 平行。。。。

alicess

从句子上来看 but前面的句子跟But 后面的句子意思上都是在说the way,意思上是平行的。所以句子结构上也要说..to ..but to...