ten years before 和ten years ago 有什么区别?

ten years before 和ten years ago 有什么区别? ten years before和ten years ago的区别? ten years ago和in ten years ago有什么区别 in ten years和after ten years 有什么区别, in ten years ,after ten years 和ten years later有什么区别? 帮我翻译一下ten years ago和 ten years before ten years ago 和 a decade ago的区别 since ten years since ten years ago区别 ago是不是等于before?比如ten years ago是不是等于ten years before等于before in ten years和ten years from now 有什么区别 in ten years' time 和 in ten years 有什么区别,请给例句 请问over ten years和in ten years有什么区别