可以用于皂苷元显色反应的试剂是（）
A．醋酐-浓硫酸
B．冰醋酸-乙酰氯
C．苦味酸钠
D．五氯化锑
E．三氯醋酸
参考答案：A, B, D, E
一个直尺的长度是20%米．______．
You but he the prizes to these gifted students at the meeting. [ ]
A. is hanging out
B. are handing out
C. are to hand out
D. is to hand out
