prep2007-7求指导

安然向人

One of the earliest known birds with a beak and contour feathers,Confuciusornis sanctus,(with large clawlike"thumbs"on its wings,which probably helped them to)climb up to a launching position for fight.A.with large clawlike"thumbs"on its wings,which probably helped it to
B.with large clawlike"thumbs"on their wings,which probably helped them to
C.had large clawlike"thumbs"on its wings,which probably helped them
D.had large clawlike"thumbs"on its wings,probably to helpe it
E.had large clawlike"thumbs"on their wings,which probably to help it
   正确答案是D。我知道根据agreement可以排除BCE。A选项没有main verb也可以排除。但对于答案D有个疑问：
   D项后面部分是不定式作状语（有省略的话我自己也没有看明白这不定式结构还原出来应该是什么），但是OG12th 语法部分第30题E选项的解释中说到：“Although the infinitive would work if it were not preceded by a comma,it cannot act as a nonrestrictive adjectival phrase modifying ...”这句话可以理解为不定式结构不能前面用逗号隔开作为非限制性修饰成分吗？按照OG这个解释就不明白这道题的D选项怎么会作为正确答案了。
  求各位牛人指导！

fengchen318

那句话应该是说，如果要是没有逗号，那个不定式结构就是对的，但是E选项吧不定式结构放在了非限定性里面，那么不定式修饰的应该是wings...那么那个it就不对了。。。我是这么理解的。。。

安然向人

请解释一下E答案。。。

fengchen318

E应该就是which用的不对。我理解这句话应该是说：这个鸟拥有 large clawlike"thumbs"这件事help it climb up to a launching position for fight....

which 不能指代整句话，用在这里指代的是wings...就变成wings help it...了

安然向人

唔。。。不好意思说错了。。。请解释一下D答案。。。

瓦利哥

同问这个题，不定式不是不可以作非限定性修饰的吗？