.Go back where you came from.

you come from不是缺宾语么 难道where在这做宾语？where 不是不能做宾语么

where you came from一起作宾语，where在此是个连接副词

这是一个定语从句。它是由两个句子构成的。where=to the place that 1.go back to the place. 2.you came from to the place. 两个句子合起来就是：go back to the place that you came from.中文意思是：回到你来的地方去。