1.Is this the factory______you visited the other day?
A.that B.where C.in which D.the one
变为陈述句就好理this is the factory that you visited the other day?定语从句,引导词that在从句中作visit的宾语.A.that
2.Is this factory______some foreign friends visited last Friday?
A.that B.where C.which D.the one
变为陈述句：this factory is the one (that) some foreign friends visited last Friday
句中无先行词,所以选the one 作factory的同位语,后接定语从句.引导词that省略.D.the one
3.Is this the factory________he worked ten years ago?
A.that B.where C.which D.the one
横线后的从句缺状语,work后接工作地点,所以定语从句用where引导.B.where