在窗体上添加一个命令按钮,编写事件过程:Private Sub Command1_Click()Dim a As Integer,b As 在窗体上添加一个命令按钮,编写事件过程: Private Sub Command1_Click() Dim a As Integer,b As Integer a=InputBox("Enter the First integer") b=InputBox("Enter the Second integer") Print b+a End Sub 程序运行后,单击命令按钮,先后在两个输入对话框中分别345和678,则输出结果是()。 A.1023 B.678345 C.678 D.345