When changing lanes, a driver should use his   turning signal to let other drivers know  ____   .   [ ]

A. he is entering which lane  

B. which lane he is entering    

C. is he entering which lane  

D. which lane is he entering

慢性肾功能不全脾肾气虚证，治疗应首选的治疗方剂是（）。

A.六君子汤

B.济生肾气丸

C.小半夏加茯苓汤

D.杞菊地黄汤

E.六味地黄丸