下列程序的功能是用辗转相除法求两个正整数的最大公约数。 Option Explicit Private Sub Command1_Click() Dim a As Integer, b As Integer, g As Integer a = InputBox("输入数字a:") b = InputBox("输入数字b:") g = (1)________ Print a; "和"; b; "的最大公约数是:"; g End Sub Private Function Gc(ByVal x As Integer, ByVal y As Integer) Dim z As Integer z = x Mod y Do While (2)_____________ x = y y = z (3)_____________ Loop (4)_____________ End Function