一般工作压力为0.2-1.3MPa的低压小锅炉,如进行锅炉水水质调整处理时,应该投加()
A.磷酸氢二锅
B.碳酸纳
C.磷酸三纳
D.氢氧化纳
参考答案:B
检索最少有3名职工的每个部门的职工工资总额
A.SELECT 部门号,COUNT(*),SUM(工资)FROM 职工表; HAVING COUNT(*)>=3
B.SELECT 部门号,COUNT(*),SUM(工资)FROM职工表; GROUP BY 部门号 HAVING COUNT(*)>=3
C.SELECT 部门号,COUNT(*),SUM(工资)FROM 职工表; GROUP BY 部门号 SET COUNT(*)>=3
D.SELECT 部门号,COUNT(*),SUM(工资)FROM职工表; GROUP BY 部门号 WHERE COUNT(*)>=3
崩解剂
A.5minB.10minC.15minD.30minE.60min