[单项选择题] 下列程序执行后，变量x的值为______。 Dim a, b, c, d As Single Dim x As Single a=100

[单项选择题] 下列程序执行后，变量x的值为______。 Dim a, b, c, d As Single Dim x As Single a=100 b=20 c=1000 If b＞a Thend=a: a=b: b=d End If If b＞c Then x=b Elseif a＞c then x=c Else x=a End If

A．100

B．20

C．1000

D．0

A