none of them / every student

none of them / every student none of them 英语中关于主谓一致"None of them is/are student"中是否该用"students"? all of them,none of them... l have none of them every means ___tired to solve theproblem,but none of them wo 请问none of them等于_____of them? none of them和none of whom的区别 every of them对吗? Both of them a student none of them为什么不用they None of them to be any good.