It was _______ that we were all greatly surprised.

题目

It was _______ that we were all greatly surprised.
A.such big fish B.such a big fish
我选A了
我想问：像fish这类词在什么情况下可数?又什么情况下是不可数?请高手具体列下

答案

fish的复数形式是fish or fishes
fish,指同一种鱼的时候单复数相同,谓语看情况用；指不同种鱼时复数fishes,这个时候当然谓语用复数啦；指鱼肉,不可数,谓语用单数；指鱼类,用单数.
It was 当然是 a fish