Only then _____ how much damage had been caused.

A．she realized

B．She had realized

C．had she realized

D．did she realize

脑脊液鼻漏时鼻内镜检查发现脑脊液来自咽鼓管，提示瘘孔在：（）

A.蝶窦

B.额窦

C.筛板

D.颅中窝

E.鼓室或乳突