"work as"和"work on"有什么区别?

work on和work as有什么区别,应如何运用 work on 和work at 和 in 有什么区别? work on 和 work at 有什么区别? work on work out有什么区别 at work,in work,on work 有什么区别? work on和work with和work to有什么区别? work on work at work for work as用法和区别 work on,work out,work in work to有什么区别求大神帮助 work on may letter和work at my letter都可以吗,有什么区别 on the work和at work区别 work at和work on和work out的区别 work hour load 和 work hour 有什么区别?