定语从句 The farm _____ my father once worked has taken on a new look now 填介词+关系代词

The farm on /at which my father once worked has taken on a new look now这边in which=where因为先行词【farm】在从句中作地点状语【my father once worked on/at the farm】在农场,介词搭配用on /at所以填on/at ...应该是on/at which=where吧嗯，打错了