—As far as I know，it is.

A．Does；belong to

B．Is；belonged to

C．Does；attach to

D．Is；attached to

【答案】D

【解析】从答语it is知道上文助动词为is，而belong to无被动语态。句意为：——那所中学附属于北京师范大学吗？——据我所知，是的。