推坎宫的功效除疏风解表，止头痛外，还有（）

A.镇静安神

B.理气化痰

C.醒脑明目

D.降逆平喘

E.补益气血

All that he had learned only made him feel how little he knew in comparison with () remained to be known.

A. what was

B. what

C. which was

D. that