原句转换成陈述句是
It was in the village_____we used to live in ____the new library was built.
第一个空后面的we used to live in是修饰village的定语从句,因为live in the village,所以此处先行词作live in宾语,所以用which.若先行词在从句中作状语,则用where,如
We went to the school where the accident happened.
第二个空填that是因为 It is/was.that...强调句式.如不看定语从句部分,则为It was in the village that the new library was built.