Sally is very happy. There is a big smile ______ her face. [ ]
A. on
B. to
C. in
D. at
答案:A
一般成人用量泼尼松多少以下为小剂量?()
A.10mg/d
B.20mg/d
C.30mg/d
D.40mg/d
E.50mg/d
如图是禁止左侧绕行标志。