[问答题] 简述阻挡层的双重作用。

You are implementing an ASP.NET Web site. The root directory of the site contains a page named Error.aspx. You need to display the Error.aspx page if an unhandled error occurs on any page within the site. You also must ensure that the original URL in the browser is not changed. What should you do？（） ["Add the following configuration to the web.config file.","Add the following configuration to the web.config file.","Add the following code segment to the Global.asax file.","Add the following code segment to the Global.asax file."] 简述消防器材的种类。 接触射击常有的改变是：（） ["射入口小于射出口","入口常呈星芒状撕裂","有时留有枪口印痕","射入口形状很不规则，创缘外翻","常有大量火药烟灰"] 赡养 Refer to the exhibit. Host A has sent an ARP message to the default gateway IP address10.10.10.1. Which statement is true？（） ["DSw1 will reply with the MAC address of the next AVF","DSw2 will reply with the MAC address of the next AVF","Because of the invalid timers that are configured， DSw1 will not reply","Because of the invalid timers that are configured， DSw2 will not reply","DSw1 will reply with the IP address of the next AVF","DSw2 will reply with the IP address of the next AVF"] 简述阻挡层的双重作用。