电信运营口商为客房提供详细计费清蚁，此项服务属于通信服务产品整体概念中的（）。
A．核心产品
B．层次产品
C．形式产品
D．附加产品
参考答案：D
--- Let’s hurry. The President is coming.
--- Oh, I was afraid that we ________.
A．already miss him
B．had already missed him
C．will miss him already
D．have already missed him
按照规范，在SBCX中，外网的ip地址配置在哪个以太网端口上（）。
A、eth1
B、eth3
C、eth4
D、eth6
