语法题 Gmat OG 2015版 第114

飞行的鸟儿

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. 如题
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，解释上说因为C会造成“海星通过过度补偿来迅速替换”，这一点我不是很理解，因为我本来就是这么理解原文的。

请大神们指点迷津，在此谢过了！

BlairWQ

by (sb's) doing 是指通过什么方式，因此会被理解为growing an extra one or two是通过the animal overcompensating。而原句中这两个动名词是并列的，不是哪个是哪个的方式。