题目

—Hey, Dave! How sunny the weather is! —Yeah! Then let's go outside and practice playing guitar. A . / ; the B . a ; the C . / ; / 答案：A下列实验操作正确的是（　　）A、用天平称食盐B、稀释浓硫酸C、配制20%硫酸铜溶液D、过滤