用于奥氏体不锈钢的隔热材料制品的氯离子含量不应大于25ppm，或应符合GBJ126—89《工业设备及管道绝热工程施工验收规范》有关规定。
参考答案：对
By the time I got home, my son _______ his homework already. [ ]
A. finished
B. have finished
C. had finished
D. will finish
全心全意为人民服务，是人民警察的宗旨。 ( )
