One way to understand thousands of new words is to have________ good knowledge of basic word formation.

A．/

B．the

C．a

D．one

苏子降气汤中配伍当归和肉桂的意义是（）。

A．温肾纳气

B．养血补肝

C．温补下虚

D．祛痰止咳

E．温肾祛寒