混凝土建筑物的漏水一般常用的处理措施有：水泥砂浆勾缝、水泥砂浆抹面、快凝砂浆堵塞漏水孔道、设置防水层和反滤排水设施等。
参考答案：错
— It is Sunday today, isn't it?
— Yes. We _____ to school today.[ ]
A. don't need go
B. need to not go
C. needn't to go
D. don't need to go
将下列气体通入水中，既能生成含氧酸，又能生成无氧酸的是
A．氯气
B．二氧化氮
C．二氧化碳
D．二氧化硫
