This is the hospital（）they visited last year and it is the one()I worked five

在前一个定语从句中,先行词作宾语,所以用that.原句是they visited the hospital last year.
在后一个定语从句中,先行词作的是地点状语,所以用where.原句为：I worked in the hospital five years ago.在后一个定语从句中,the hospital 不是做宾语吗，为什么作的是地点状语？in the hospital一起做地点状语先行词不是the hospital 吗，怎么变成in the hospital了定语从句中没有出现介词in， 所以要用in which 或者where。