单选题 单击命令按钮，并在对话框内依次输入5，7，6下列程序段的执行结果为______。 Private Sub Command1_Click() Dim n AS Integer, a As Integer, b As Integer, c As Integer n = 0 For i = 1 To 3 a = InputBox ("请输入数字") n = n+a*a If n ＞ 50 Then GoTo ex End If Next i ex: Print n End Sub