阅读程序： Option Base 1 Dim arr()As Integer Private Sub Form_Click() Dim i As Integer,j As Integer ReDim arr(3,21 For i=1 To 3 Forj=1 To 2 arr(i,j)=i*2+j Next Next ReDim Preserve arr(3,4) For i=3 To 4 arr(3,j)=j+9 Next Print arr(3,2)+arr(3,4) End Sub 程序运行后，单击窗体，输出结果为( )。