食管裂孔疝的手术指征是（）

A.症状明显的滑疝

B.食管旁疝

C.混合型裂孔疝

D.多器官裂孔疝

E.巨大型食管裂孔疝

Someone called me up in the middle of the night, but they hung up ____I could answer the phone.

A．as

B．since

C．until

D．before