_____________ the ability to speak, so he used sign language to communicate with others.

A．As he lost

B．He lost

C．Having lost

D．His being lost

硬食管镜检查的并发症包括（）。

A.食管黏膜损伤出血

B.食管穿孔

C.诱发支气管哮喘

D.迷走神经反射性心跳骤停

E.环杓关节损伤