Private Sub Text1_Change()

  Dim c As Integer, i As Integer

  i=0

  c = Val(Text1.Text)

  Do While c >= 0

    c = c - i

    i = i + 1

  Loop

  Text1.Text = Str(c)

End Sub

在文本框输入“6”，执行该程序段后， 其中c >= 0执行的次数是（  ）

程序部分代码如下：

Private Sub Command1_Click()

Dim n, m, s, i, j, count As Long

Dim flag As Boolean

Dim a(1 To 100) As Integer

n = Val(Text1.Text)

count = 0

  ①  

For i = 0 to s-1

 m = i

 For j = 1 To n

 a(j) = m Mod 2

 m = m \ 2

Next j

flag = True

For j = 1 To n - 1

 If  ②  Then flag = false: exit For

Next j

If flag = True Then  ③  

Next i

Label1.Caption =“可行方案共”+ Str(count) + “种”

End Sub

图a

图b

Dim a(1 To 6) As Integer

Randomize

a=n Mod k

n=n\k,k=k+1,s=s+a

a(1) = Int(11 * Rnd) + 2

For i = 2 To 6

a(i) = Int(11 * Rnd) + 2

If i Mod 2 = 1 And Not prime(a(i)) Then i = i - 1

ElseIf Not prime(a(i)) Then a(i) = a(i) + a(i - 1)

End If

Next i

'自定义函数 prime()用于判断参数是否为质数，prime(n) = True 则说明 n 为质数，否则为合数，定义函数代码略执行该程序后，a(1)～a(6)的值不．可．能．为（  ）

lst = [2,5,2,1]

y = [1,1,1,1]

n = len(lst)

for i in range(①____):

    for j in range(②____):

        if ③____:

            y[j] = y[j] + 1

        else

            y[i] = y[i] + 1

上述程序段3个划线处的表达式分别为（   ）