Primary和basic和elementary的区别

asic：“基础的、基本的、根本的”,常有“起点”性质,可用来修饰抽象概念,也可用来强调确切、具体的基础或根基.
At least,you should have taken into account the plan in its basic aspects.至少,你本应考虑到此项计划基本方面.
elementary：“初步的、基础的”,着重指基本的或开始的事物,也指初步的概念和原则、必要的因素及组成部分.
John learned addition and subtraction in elementary arithmetic.约翰在初等数学中学习了加减法.
How can you expect to succeed without even the elementary knowledge of the field?没有这一领域的最基本知识,你怎能指望成功呢?
primary：“最初的、主要的”,表示在进展顺序中居于首位,意为：“最初的”,或指复杂构造中的基础部分,意为“主要的”,还指在重要性方面具有主导地位,意为“最重要的、主要的”.
We were relieved to hear that his disease was still in its primary stage.得知 他的病仍处于初始阶段,我们感到很宽慰.