a variety of 的用法a variety of food还是foods,a large number of 用可单还是可复

问题描述:

a variety of 的用法
a variety of food还是foods,a large number of 用可单还是可复

a variety of 是加复数的,但是food比较特殊,既是可数名词,又是不可数名词,a variety of food                      a large number of +名词复数