在窗体上画一个命令按钮,名称为Commandl,然后编写如下事件过程. Option Base 0 Private Sub Command1_Click Dim city As Variant city=Array(“北京”,“上海”,“天津”,“重庆”) Print city(1) End Sub 程序运行后,如果单击命令按钮,则在窗体上显示的内容是
【单选题】It is generally believed that the main reason for the formation of acid rain in China is that ( ) and other acidic gases enter the atmosphere and gradually form acidic precipitation with PH < 5 and 6.