40. To meet the rising marketing demand for fish and seafood, suppliers are growing fish twice as fast as their natural growth rate, cutting their feed allotment by nearly half and raising them on special diets.

A. their natural growth rate, cutting their feed allotment

B. their natural growth rate, their feed allotment cut

C. growing them naturally, cutting their feed allotment

D. they grow naturally, cutting their feed allotment

E. they grow naturally, with their feed allotment cut

D: correct

要对称的对象应该是growing fish 吧~~C应该比D更加对称的么～ 为什么答案这样说呢？

这里所谓的对称是比较 twice as fast as 前后的部分

Suppliers are growing fish ...和 they grow natrally

首先，C如果要对称必须补出助动词are，不然就是动名词，当然不对称

其次，句子的结构对称不代表时态一定要对称

natuarally明显是平时一般的做法，用进行时不妥当

同意ls,另外,C的逻辑意思也不对啊

正确的意思是grow是非急务动词,是鱼自己的生长速度

而C的意思是养鱼