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

ten years before 和ten years ago 有什么区别? 帮我翻译一下ten years ago和 ten years before ago是不是等于before?比如ten years ago是不是等于ten years before等于before ten years before ten years与ten years before含义一样吗?造句 ten years before和ten years ago的区别?那说的不都是过去的事情吗？怎么会是一般现在时啊？ in ten years和after ten years 有什么区别, in ten years和for ten years的区别 The hospital has been open ____ A.for ten years before B.since ten years agoC since ten years D ten years ago Where had the kings lived for ten years before they came here.这里为什么会同时用had和lived ten years old 和ten-year-old的区别 as和as if作为好像的意思时有什么区别?比如说这两个句子：He looked just as he had looked ten years before.She looked as if she were ten years younger. in ten years ,after ten years 和ten years later有什么区别?in ten years 是十年之后还是十年之内? Scientists say it may be ten years _____ this medicine was put to use.A since B before C after D.when 给出正确答案,理由和翻译 Scientists say it may be ten years _____ this medicine was put to use.A since B before C after D.when 给出正确答案,理由和翻译 in ten years' time 和 in ten years 有什么区别,请给例句 ten years ago和in ten years ago有什么区别 after ten years 和after ten years time 有什么区别 in ten years和ten years from now 有什么区别