请教大家一个to do用法的问题

AmyGMAT

请教大家一个to do用法的问题
具体的题目我找不到了，但是我记得包括OG上都有这样的解释：to do不定式之前不可以有逗号，即SVO，to do这样的用法是错误的
但是在做题的时候偶尔也会碰到这样的用法
所以我想请教各位nn，上面所说的有上面前提吗？
比如prep2-13
One of the earliestknown birds with a beak and contour feathers, Confuciusornis sanctus, with largeclawlike “thumbs” on its wings, which probably helped them to climb upto a launching position for flight.
A. with large clawlike “thumbs” on its wings,which probably helped them to
B. with large clawlike “thumbs” on their wings,which probably helped it to
C. had large clawlike “thumbs” on its wings, whichprobably helped them
D. had large clawlike “thumbs” on its wings, probably to help it 正确
E. had large clawlike “thumbs” on their wings,probably to help it

D项就用了“，to do”的形式这里不是很明白，是这里用法比较特殊吗？
请指教！

AmyGMAT

help me please~~!!

pennyconan

你说的是斑竹的这句话吗？
不定式位于句尾，使用逗号与前句隔开――这种结构是一种错误的结构。

AmyGMAT

对对！！

AmyGMAT

The features of the floor of the Kasei Valles on Mars look just like those at the base of Antarctic ice streams, so it suggests that possibly it was flowing ice that carved the giant Martian channels previously attributed to cataclysmic floods.
(A) so it suggests that possibly it was flowing ice that
(B) a suggestion that flowing ice may have
(C) to suggest flowing ice as possibly having
(D) suggesting that flowing ice may have
prep2-122
这道题C项错了就是这个原因 很晕
OG里也有
(E) which is suggestive of flowing ice having possibly

pennyconan

这里的逗号是为了with这个独立主格加的，上面那道是为了to do加的。
MM觉得呢？

AmyGMAT

sorry
我没明白你的意思...
第一题正确答案是D 没有with独立主格，为什么会是为了它加的呢？？

pennyconan

。。。看岔了。。。 MM你的字太小了-- 我也不知道了。。。

AmyGMAT

哦哦 改过来了~
thank you all the same

aeoluseros

嗯，感谢AmyGMAT，不定式总结帖里面当初这点确实需要继续讨论，不过你给我的例子足够推翻了那个结论了:-D。
=======================
2-13  One of the earliestknown birds with a beak and contour feathers, Confuciusornis sanctus, with largeclawlike “thumbs” on its wings, which probably helped them to climb upto a launching position for flight.
A. with large clawlike “thumbs” on its wings,which probably helped them to
B. with large clawlike “thumbs” on their wings,which probably helped it to
C. had large clawlike “thumbs” on its wings, whichprobably helped them
D. had large clawlike “thumbs” on its wings, probably to help it 正确
E. had large clawlike “thumbs” on their wings,probably to help it
umm……这里to help是状语，修饰had，看来不定式作状语应该可以用逗号隔开的。不过个人觉得probably的存在有了更应该用逗号隔开的感觉，因为probably表达了一种强调(就如同although如果在句中出现引导从句时，前面总是有逗号)，所有前面要有逗号；并且如果probably没有逗号会觉得生硬，并修饰不清。
open to discuss.
===================
2-122  The features of the floor of the Kasei Valles on Mars look just like those at the base of Antarctic ice streams, so it suggests that possibly it was flowing ice that carved the giant Martian channels previously attributed to cataclysmic floods.
(A) so it suggests that possibly it was flowing ice that
(B) a suggestion that flowing ice may have
(C) to suggest flowing ice as possibly having
(D) suggesting that flowing ice may have
是因为后面应该是跟一个伴随状语，而不是to suggest。用不定式并不是因为“用了不定式这个形式而错”，而是因为用了不定式以后表达的逻辑含义错。