His father has worked in this factory he came here in 1980.A. since B. for C. when

问题补充：

His father has worked in this factory he came here in 1980.

A. since B. for C. when

答案：

解析：since由于，自从……以来；for为了，对于；when当……时。句意：自从他1980年到这儿以来，他的父亲就在这家工厂工作。故选A。