OG13 114 求解释，万谢

fzxfff

Starfish, with anywhere from five to eight arms, have a strong regenerative ability, and if one arm is lost it quickly replaces it, sometimes by the animal overcompensating and growing an extra one or two.

(A) one arm is lost it quickly replaces it, sometimes by the animal overcompensating and

(B) one arm is lost it is quickly replaced, with the animal sometimes overcompensating and

(C) they lose one arm they quickly replace it, sometimes by the animal overcompensating,

(D) they lose one arm they are quickly replaced, with the animal sometimes overcompensating,

(E) they lose one arm it is quickly replaced, sometimes with the animal overcompensating,

答案是B，我选的C

前半句B的主语是one arm, C的是they（starfish）和and前面的句子主语一致，不应该更合理吗？（虽然两个都没错）
然后后半句就更不明白了，C我理解的是by overcompensating 这种方式来replace arm， 然后逗号后面growing...是来解释overcompensating是什么样的方法的。。。
我的想法错在哪？
谢谢大家的解答

guaiss

提供一个GMATCLUB上的解释
use of by is improper in an active voice setting. It should be with the animal rather than by the animal; overcompensating, growing is improper co-ordination. There should be an and in between

fzxfff

guaiss 发表于 2013-10-27 12:28
提供一个GMATCLUB上的解释
use of by is improper in an active voice setting. It should be with the ani ...

为什么主动语态用by就improper了？

zhudanqing

fzxfff 发表于 2013-10-27 15:57
为什么主动语态用by就improper了？

lz，这里有一个很重要的知识点：
逗号+Ving 形式在用的时候时候有条件，即这个动作必须与前面的句子有绝对的逻辑关系。

zhudanqing

来自ron 关于comma+Ving 用法的详细解释：楼主请戳下面。。。

所以读完后你会发现：这种用法不能用来表示解释说明。！！这也是以前我们自己写作文的时候经常会犯的并觉得是对的错误= =

逗号+VING 1表伴随，同时发生；2表结果；没有第三了！

"* 关于comma+Ving的补充（详细版）：
the ""comma + ing"" modifier should only be used when:
(A)【跟主语的关系，逻辑主语必须一致】不一定是主句主语
it MODIFIES THE ENTIRE ACTION of the preceding clause, and it APPLIES TO THE SUBJECT of that clause;【修饰整个之前的句子，逻辑主语必须是句子的主语】

AND

(B)【跟 main action 的关系--时间上同时从属，或者 关系上 从属】
one of the following is true:

(1) the ""ing"" action is SIMULTANEOUS with, and SUBORDINATE to, the main action;
- i ran down the sidewalk, flapping my arms wildly
(2) the ""ing"" action is a DIRECT AND IMMEDIATE CONSEQUENCE of the main action.
- i got a 100 on the most recent exam, bringing my average up to 91

since COMMA + -ING clauses are automatically attributed to the SUBJECT of the preceding clause, this modifies the moon.
as it clearly should, in context.

also note that it applies not only to that subject, but to the entire action of that clause (this is what makes it ""adverbial"")."

fzxfff

zhudanqing 发表于 2013-10-27 19:02
来自ron 关于comma+Ving 用法的详细解释：楼主请戳下面。。。

所以读完后你会发现：这种用法不能用来表示 ...

十分感谢~