difference 表示"差异,差别",可数:There are many differences between living in a city and living in the country.生活在城市和生活在乡村有许多不同之处.difference 表示"差额,差数",不可数:The difference between 5 and 11 is 6.十一和五的差是六.
(1)可以当可数名词 差别 ,差异, 不同 所以可以用a difference 或differences e.g. There is a difference between A and B . There are some differences between A and B .所以你所说的句子可以用:What is the difference of A and B? What are the differences of A and B?(2)可以当不可数名词 差额;差;差距e.g. I can't see much difference in them. 我看不出他们有什么大的差别。