求助一道og语法题 ：to do 平行结构

fantasy198

[size=13.63636302948px]   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.

[size=13.63636302948px]A. the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid

[size=13.63636302948px]B. forming the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them

[size=13.63636302948px]C. having bricks formed from mud or clay, and, after some preliminary air drying or sun drying, they were laid

[size=13.63636302948px]D. to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them

[size=13.63636302948px]E. that bricks were formed from mud or clay, which, after some preliminary air drying or sun drying, were laid

这道题D选项，经过抽取句子主干------to form， and to lay 有没有问题？ 我觉得应该是 to form and to lay，也就是说bricks后面不加逗号。

先谢谢~

fantasy198

还是没明白 compound sentence 逗号后面的第二句有连接词的话应该有主语。如果不是不是compound sentence 就应该没有逗号，to do and to do吧？   

kiwifoodtown

LZ,这个不是并列，to form 和 to lay 不是两个并列的过程，而是有先后顺序的两个相对独立的过程。所以以逗号分离表示其先后关系。比如这句 There is wit enough, and to spare.  另外说一下，如果真是两个不定式并列那and后的to通常省略,应该是 to do and do.

fantasy198

kiwifoodtown 发表于 2015-1-21 09:32
LZ,这个不是并列，to form 和 to lay 不是两个并列的过程，而是有先后顺序的两个相对独立的过程。所以以逗 ...

谢谢，懂了！