After he became conscious, he remembered __________ and __________ on the head with s rod.

A．to attack; hit

B．to be attacked; to be hit

C．attacking; be hit

D．having been attacked; hit

中国药典规定，苯甲酸钠含量测定采用双相滴定法，其所用的溶剂体系是（）

A.水-乙醇

B.水-醋酸

C.水-乙醚

D.水-氯仿