Was the factory ____ your father once worked_____ we visited

Was the factory ____ your father once worked_____ we visited Is the factory --------we visited last year Is this the factory( )we visited yesterday? The first factory()we visited last Sunday was set up in 1950 we visited the factory ---I have visited all my lost? Is that factory which your father once worked in? 1.-where did you see him? -It was in the factory( )we once w This is the factory where we visited last week. Is this the factory _____ we visited last week? We have visited the factory (twice).(对括号部分提问) Is this the factory---------we visited all my life. This is the factory (that/which)we visited yesterday.