1. (2020高二上·上虞期末) 有如下VB程序段：

Dim i As Integer

Dim c As String， s As String， t As String

s = "2021 PYthon": t = ""

For i = 1 To Len(s)

    c = Mid(s， i， 1)

    If c >= "a" And c <= "z" Then

        t = t + c

    ElseIf c >= "0" And c <= "9" Then

        t = c + t

    End If

Next i

Text1.Text = t

执行该程序段后，文本框Text1中显示的内容是（    ）