求助一个小问题：平行结构中to省略问题

vilawe

OG12 11
There are several ways to build solid walls using just mud or clay, but the most extensively used method has been to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them  in the wall in mud mortar.
OG12 15
Warning that computers in the United States are not secure, the National Academy of Sciences has urged the nation to revamp computer security procedures, institute new emergency response teams, and create a special nongovernment organization to take  charge of
computer security planning.
OG12 51
A new study suggests that the conversational pace of everyday life may be so brisk that it hampers the ability of some children to distinguish discrete sounds and words and, as a result, to make  sense of speech.
OG12 55
Many house builders offer rent-to-buy programs that enable a family with insufficient savings for a conventional down payment to
move into new housing and to apply  part of the rent to a purchase later.
OG12 62
When Congress reconvenes, some newly elected members from rural states will try to establish tighter restrictions on the amount of
grain farmers will be allowed to grow and to encourage  more aggressive sales of United States farm products overseas.
这几个平行结构的例子里，只有15题省略了to，其他的都没省略。to在平行结构里省略是有规则的还是除了第一个to不能省，其他的可省可不省？
想了一天这个问题了，还是没有看出什么规律，请各位XDJM来帮忙啊

vilawe

自己把它顶起来……

vilawe

我再顶……

vilawe

省略的原则是成分相同，这里的这些to所起的作用相同啊，求讨论……这个问题是不是太低级了，大家都不想回答啊……请大家指点一下小女子啊

弗拉多

15题OG的解释是
to (1) revamp (2)institute (3)create

个人理解如果出现了3个或以上的平行，最好省去，否则 to revamp to institute to create这样的结构实在不符合ETS的Concision原则

那么2个动词的平行，就不一定了
比如OG12-71

vilawe

好像是有这样的规律，三个to显得太多了，两个并列结构的（除了55题）大多数时候之间都有些插入语之类的，隔了较长距离，加一个to可能可以起到一个更好显示出平行结构的作用， 如果两个并列近，那省掉第二个to会显得句子更简洁

弗拉多

哈哈 LZ我猛然翻倒了对3个to平行的OG解释，在OG12-108题对C选项的解释，我打过来

To preserve parallelism, the infinitive marker TO should appear ONLY before the first verb in the series OR it should appear before all three verbs

^^

vilawe

那意思就是可省可不省了哦，如此看来，这个问题的讨论貌似没有意义……但是了了心里疑惑还是很好，谢谢啦

vilawe

今天又看到了两个成分平行的OG解释，117题 While it is not essential to repeat to, the repetition elegantly reinforces the parallelism.

秋叶蠖

to的平行结构，除了第一个不能省外，其余的要么全省要么全保留。