锅炉水质不良.对锅体的损害也是严重的.一般有以下三种情况:⑴.由于水质硬度高.造成结渣损坏炉管;⑵.氧腐蚀损坏炉管;⑶.()。
参考答案:由于溶解盐的的腐蚀而损坏炉管
Playing QQ’s “Happy Farm” by planting, watering, fertilizing, spraying, harvesting and selling of virtual vegetables, fruits and flowers, we can find out all the excitement is about.
A.that
B.if
C.what
D.when
工程项目设计应在项目( )阶段完成。
A.决策 B.准备 C.实施 D.验收