有如下Visual Basic程序段：
x=2.1Ifx>6.0Then
Label1.Caption="Pass"
Else
Label1.Caption="Fail"
EndIf
该程序段运行后,Label1标签上显示为_____________

公元6世纪，中国的《张丘建算经》有一道著名的百鸡问题：公鸡5钱1只，母鸡3钱1只，小鸡3只1钱，有人用100钱买了100只鸡。请编写一段代码求其中公鸡，母鸡，小鸡各多少只？
Private Sub Command1_Click()
For i =" 0" To 20
For j =" 0" To 33
k =    
If     Then Print i, j, k
Next j
Next i
End Sub

统计数字子串之和。用VB编写程序，在文本框Text1中输入任意字符串s，统计s中数字字符串的数值和（如输入字符串“ab123dr34fg9de”，则输出 166，即 123+34+9＝166），并在Label3输出结果。程序设计界面如下：

Private Sub Command1_Click()
Dim s As String, ch As String
Dim ch2 As String, sum As Double
Dim n As Integer, i As Integer
s = Text1.Text
①________
i =" 1:" sum = 0
Do While i <= n
ch =" Mid(s," i, 1)
If ch >= "0" And ch <= "9" Then
②________
ch2 =" Mid(s," j, 1)
Do While ch2 >= "0" And ch2 <= "9"
j =" j" + 1
ch2 =" Mid(s," j, 1)
Loop
sum =" sum" + ③________
i = j
End If
i =" i" + 1
Loop
Label3.Caption = Str(sum)
End Sub

代数式改成VB表达式是_______。

A．a/b+c/d

B．a/(b+c)/d

C．(a/b+c)/d

D．a/(b+c/d)

将1、1、2、3、5、8、13、21、……数列的前20项存入a数组的正确程序段是_______。

A．	B．
C．	D．