—What were you doing this time yesterday? 　　

—I ______ on the grass and drawing a picture. 　　[ ]

A. sit

B. sat

C. am sitting

D. was sitting

组成药物中含有牡丹皮的方剂是（）

A.大黄牡丹汤

B.凉膈散

C.普济消毒饮

D.青蒿鳖甲汤

E.清瘟败毒饮