“晴雨表”是形容舆情信息工作关于（）方面的作用。

A.管理民情民意

B.积极调控社会心态

C.有效防范社会风险

D.及时化解社会矛盾

It was last year _____ I visited the museum _____ you had visited.

A．that; that

B．when, where

C．that; where

D．when; that