1. (2020·浙江模拟) 维吉尼亚(Vigenere)密码。如下图所示，分别用行和列表示待加密的字符(明文)和当前字符的密钥，行和列的交叉点的字符即为加密后的结果(密文)。在加密时，密文与明文的字母大小写形式保持一致，如，明文字母为大写，则加密后的密文字母也为大写；当密钥长度不足时重复使用密钥。例如：当明文M=HelloWorld，密钥K=abc时，密文C=HfnlpYosnd。运算过程如下所示：

明文：HelloWorld

密钥：abcabcabca

密文：HfnlpYosnd

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依据上述算法描述设计了如下VB程序。请回答下列问题：

1. （1） 若明文是Jia，密钥是Pass，则输出的密文是：。
3. （2） 请在横线处填上合适的代码。

   Const MIN_ASC = 65       ′字母“A”的ASCII值

   Function X2D(x As String) As String     ′字符串小写转成大写

   Dim s As String, zf As String, i As Integer

   s = “”

   For i = 1 To Len(x)

   zf = Mid(x, i, 1)

   If zf >= “a” And zf <= “z” Then

               s = s +

   Else

         s = s + zf
             End If
       Next i
       X2D = s

   End Function

   Private Sub Command1_Click()

   Dim M As String, K As String, C As String, flag As Boolean

   Dim i As Integer, t As Integer, ch As Integer, pos As Integer, j As Integer

   M = Text1.Text             ′明文

   K = Text2.Text              ′密钥

   t = Len(K)

   K = X2D(K)                   ′将密钥全部转成大写

   C = “ ”                      ′加密后的结果

   For i = 1 To Len(M)

   ch = Asc(Mid(M, i, 1))

   flag = False

   If ch >= 97 And ch <= 122 Then ch = ch - 32: flag = True

     pos =                ′密钥的字符位置值

   If pos = 0 Then pos = t

         j = Asc(Mid(K, pos, 1))               ′密钥字符的ASCII值

        ch = ch - MIN_ASC

        j = j - MIN_ASC

         ch =

         ch = ch + MIN_ASC

     If flag Then ch = ch + 32         ′设置字母的大小写形式

        C = C & Chr(ch)

   Next i

   Text3.Text = C

   End Sub