请教PREP 1

1.       (24465-!-item-!-188;#058&000982)

To meet the rapidly rising market 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

想问一下这道题目，为什么在修饰fish的时候用their呢？我怎么记得fish是不可数名词应该用单数啊？谢谢大家。

顶啊！

顶啊！

fish也可以做复数的

答案是A还是C?

原来fish也可以做复数啊，害我一开始把D E排除了。还有什么词是单复同型的？