A good friend of mine from when I was born showed up at my home right before I left for Beijing. 其中A good friend of mine是主语;from when I was born 是主语的补语,对主语其限制作用,告诉我们是怎么样的一个朋友;show up是宾语,表出现;at my home right是补语,表show up的地方;before I left for Beijing是从句。 整句话的意思是:在我离开这里前往北京之前,我青梅竹马的一个好朋友刚好来我家看我。