【单选题】Bottom blow valves are installed on auxiliary water-tube boilers to ___________.
A.
completely drain the boiler in an emergency
B.
prevent sludge from forming in the drum
C.
remove floating impurities from the boiler water surface
D.
remove settled solids from the water drum
【单选题】肝细胞病变时,下列血清蛋白浓度不减少的是
【简答题】**操作题 ** 1、打开工作簿文件 EXCEL.XLSX,(1)将shee1工作表的A1:D1单元格合并为一个单元格,内容居中;计算总计列、“优秀支持率”(百分比型,保留小数点后1位)列和“优秀支持率排名”(利用RANK函数,降序);利用条件格式的“数据条”下的“实心填充“修饰A2:B8单元格区域(2)选择“学生“和“优秀支持率两列数据区域的内容建立分离型三维饼图”,图表标题为优秀支持率统计图”...
【单选题】Auxiliary boilers can be classified as .
A.
water-tube natural circulation boilers
C.
water-tube forced circulation boilers
【多选题】混凝土浇筑过程中应注意的事项主要有( )。
A.
混凝土运输、浇筑及间歇时间的总和应小于其初凝时间
D.
减少水泥用量,掺加粉煤灰可防止大体积混凝土产生裂缝
【单选题】Bottom blow valves are installed on auxiliary water-tube boilers to _____.
A.
remove suspended and precipitated solids from the boiler water
B.
completely drain the boiler in an emergency situation
C.
prevent hardened scale deposits in the water drum
D.
remove floating impurities from the oily water surface
【简答题】可用性的三个目标是:有效性,效率,()。