【单选题】编写如下程序: Private Sub Form. Click() a$=: '4321': b$='abcd' For 3=1 To 4 Print Mid$(a$,5-j,1)+Nid$(b$, j, 1); Next j Print End Sub 程序运行后,单击窗体,其输出结果为 ______。
【简答题】在窗体上画一个命令按钮,其名称为Command1,然后编写如下事件过程:Private Sub Command1_Click() a$ = "National Computer Rank Examination" n = Len(a$) s = 0 For i = 1 To n b$ = Mid(a$, i, 1) If b$ = "n" Then s = s + 1 End If Next i ...