1)realize,vt.实现，认识到;vi变卖产业为现钱2)achieve,vt.实现，完成;达到，得到vi.达到预期目的3)realise['riəlaiz],v.(realize)认识到,体会到;实现4)real knowledge,现实认识5)recognition of the reality,认识现实6)refer,vt.把…归诸，认为…起源(于);vi. 谈到，涉及
用法和例句
Virtual knowledge is different from real knowledge, but, virual knowledge on the basis of real knowledge, depends upon real knowledge.