石灰乳用于地面消毒室的适宜浓度为:( )。
A、1%-2%
B、3%-4%
C、5%-6%
D、7%-8%
E、10%-20%
第1题:
A、1%
B、2%~2.5%
C、3%~4%
D、4%~5%
E、5%~6%
第2题:
第3题:
设W为样本空间,A,B,C是W中的事件,W={1,2,…,10}, A={1,3,5,7,9}, B={2,4,6,8,10},C={6,7,8,9,10},则AÈB-AC-BC=().
A.{1,3,5,7,9}
B.{2,4,6,8,10}
C.{1,2,3,4,5}
D.{6,7,8,9,10}
第4题:
第5题:
下列数组声明初始化语句,________是正确的。
A.Dim a() As Single={1,2,3,4,5,6,7,8,9,10}
B.Dim a(9) As Single={1,2,3,4,5,6,7,8,9,10}
C.Dim a() As Single={1,”a”,”bc”,4,5,6,7,8,9,10}
D.Dim a(, ) As Integer={1,2,3,4,5,6,7,8,9,10}
E.Dim a() As Integer=(1,2,3,4,5,6,7,8,9,10)