有如下VB程序段
Private Sub Command1_Click()
Dim s As Integer
Dim i As Integer
s = 0
For i =" 1" To 20 Step 2
If s < 20 Then
s =" s" + i
End If
Next i
Text1.Text = Str(s)
Text2.Text = Str(i)
End Sub
执行以上程序后，变量s和i的值分别为

A．9  20

B．16   21

C．25  11

D．25  21

在窗体上画一个名称为Command1的命令按钮，然后编写如下事件过程：
Private Sub Command1_Click()
Dim n As Integer
Dim m As Integer
m = 0
For n =" 1" To 20
If n Mod 3 <> 0 Then m =" m" + n \ 3
Next n 
Text1.text = Str(m)
End Sub
程序运行后，如果单击命令按钮，则文本框Text1中显示的内容是    (    )

A．15

B．18

C．42

D．24

编写“英文文章整理”程序，实现如下功能：点击“整理”按钮对任意输入的英文文章进行整理，整理规则为：所有句子开头为大写字母，其他都是小写字母，句子结束符为“.”“?”或“!”；所有标点符号后面都空一格；英文的标点符号都为半角符号。程序运行界面如图所示。

请根据算法将下列程序补充完整。
Private Sub Command1_Click()
Dim Y As String, Z As String, X As String, L As Integer, t As String
Y = ""
X = Text1.Text
L = Len(X)
For i = 1 To L
Z = Mid(X, i, 1)
If Z >= "a" And Z <= "z" Then '第一个是小写，转大写
If i = 1 Then Z = Chr(Asc(Z) - 32)
ElseIf Z = "!" Or Z = "." Or Z = "?" Then '标点后面有一个空格，一个大写
1___________
If t = " " Then i = i + 1
Z = Z & " "  '算空格
If i < L And 2_______________ Then
Z = 3_____________   '后面字母要大写
i = i + 1
End If
ElseIf Z >= "A" And Z <= "Z" Then
Z = Chr(Asc(Z) + 32)
End If
Y = Y & Z
Next i
Text2.Text = Y
End Sub

有如下 Visual Basic 程序段： 
S = 0
For i = 1 To 5

s = s + i  

Next i
If i <= 5 Then
Text1.Text = Str(s)
Else
Text1.Text = Str(s + i)
End If
该程序段运行后，在文本框Text1中显示的是

A．5

B．6

C．15

D．21

个位数字是6，且能被3整除的3位数共有多少个？下面程序用于解决这一问题，在划线处填入合适的语句或表达式，设共有n个这样的数，Visual Basic程序如下：
Sub Command1_Click()
Dim i As Integer, n As Integer
m = 106
n = __________
Do While m <= 996
If _______________________ Then n =" n" + 1
m=m+10
Loop
Text1.Text = Str(n) zxxk
End Sub