A group of sheep are eating grass and leaves at the foot of the hill.

题目

A group of sheep are eating grass and leaves at the foot of the hill.
这个句子中 grass为什么不用复数 而leaf用复数

答案

grass 是不可数名词,没有复数,而LEAF 是可数名词,复数是leaves
That man made the boy obey him.