闸阀安装套什么定额:“none of them could not do it”是什么意思？有点晕～～

“none of them could not do it”是什么意思？有点晕～～ none of them 和no one of them 的区别 “They have none of them much to recommend them”中的两个“them”分别怎么解释，代指什么。 If six children and two dogs were under just one umbrella,how come none of them got wet 用none of造句 of them和of which some和some of，none和none of的区别 both them还是both of them?为什么？ some of them 为什么要用them? None of you stuff 是什么意思？