实现上述功能的VB程序如下，但横线处代码有错，请改正。

Private Sub Command1_Click()

    Dim a As String

    Dim x As Integer, s As Integer, k As Integer

    a = Text1.Text

    x = 1: s = 0: k = 0

    For i = 1 To Len(a)

        '如果输入的不是0到9的数字或者空格，则给出错误提示后结束子程序

        If (Asc(Mid(a, i, 1)) < 48 Or Asc(Mid(a, i,1)) > 57)  or(Asc(Mid(a,i,1))= 32)  then’{#blank#}1{#/blank#}Label1.Caption = "只能输入数字或空格"

            Exit Sub

        End If

        If Mid(a, i, 1) = " " Then

            s = s + Mid(a,x,i)’{#blank#}2{#/blank#}

            x = i + 1

            k = k + 1

        End If

    Next i

    Label1.Caption = "这" + Str(k) + "个数的和为:" + Str(s)

End Sub

实现上述功能的VB 代码如下，其中加框处代码有错，请改正。

Dim n As Integer, i As Integer, t As Integer, sum As Long, s As String n = Val(Text1.Text)

For i = 1 To n ^ 3 Step 2

    sum = 0: t = i: flag = False

    Do While sum <= n ^ 3 And flag = False

       sum = sum + t

            ⑴

       If sum = n ^ 3 Then flag = True

    Loop

    If flag = True Then Exit For

Next i

s = Str(n) + "^" + Str(3) + "="

Do While sum > 0

         ⑵

    If sum = 0 Then

        s = s + Str(i)

    Else

        s = s + Str(i) + "+"

    End If

    i = i + 2

Loop

Text2.Text = s

⑴{#blank#}1{#/blank#} ⑵{#blank#}2{#/blank#} 

实现上述功能的VB程序如下：

Dim a(1 To 5) As Integer

t=0

For i = 1 To 5

  a(i) = Int(Rnd * 30 + 10)

  t = t + a(i) \ 10

Next i

For j = 1 To t \ 3

  If j Mod 2 = 1 Then a(j) = a(j) + 1 Else a(j) = a(j) - 1

Next j

运行程序后，数组a各个元素的值，不可能的是（  ）

>>> a=8

>>> b=2

>>> a-=b

>>> b+=a

>>> a+b