单项选择题
A.1000g/0.1g 电子天平B.500g/0.1g 电子天平C.1000g/1g 架盘天平D.500g/0.1g 架盘天平
A.3FL/2bh2B.3FL/2bhC.2FL/3bh2D.2FL/3bh
A.普通减水剂B.高效减水剂C.早强型减水剂D.缓凝型减水剂