The beer can is ____________ us. [ ]
A. in front
B. front
C. in front of
答案：C
既为喉科亦是眼科的常用药是()
A.铅丹
B.青葙子
C.夏枯草
D.硼砂
水资源费的缓交期限最长不得超过（）日
A.30
B.60
C.90
D.120
