16.在Visual Basic中,有如下程序: Private Sub Command1_Click( ) Dim a As Integer,b As Integer,c As Integer,d As Integer a=Val(Text1.Text):b=Val(Text2.Text):c=Val(Text3.Text) d=min(a,b)-min(b,c):Text4.Text=Str(d) End Sub Function min(x As Integer,y As Integer) As Integer If x<y Then min=x Else min=y End Function 運行該程序,在文本框Text1、文本框Text2、文本框Text3中分別輸入2、-5、6后,單擊命令按鈕Command1,文本框Text4中顯示的是( )