[填空题] 下面这个Sub过程的功能是统计字符串中“a”的个数，请在空白处填上合适的代码完成程序。 Private Sub numCount()Dim hum As Integers＄ = &qu

[填空题] 下面这个Sub过程的功能是统计字符串中“a”的个数，请在空白处填上合适的代码完成程序。

Private Sub numCount()

Dim hum As Integer

s＄ = "software And hardware"

num = Len(s$)

For i = 1 To hum

b$=______

If b$ = "a" Then x = x+1

Next i

Print "x="; x

End Sub