单项选择题
This is the problem（）we have no good solution as yet.
A.to that B.which C.for which D.to which
单项选择题 Last month, he paid a visit to the village（）he had once worked for five years.
单项选择题 Mr. Liu,（）at university in Changchun, works at Changhou Company now.
单项选择题 Let's go to the cinema,（）?
