● 某主机的 IP地址为 10.100.100.01/20，其子网掩码是 （70） 。

（70）

● A  (75)  system placed between the company network and the outside world may limit outside access to the internal network.

   (75)

● The Internet is an open system, and most information is available to everyone. It is very important to add   (74)   to existing system for protecting   the secret information.

   (74)

● The  (72)  is a collection of modules serving as interface between hardware and software to provide a software platform.

(72)

● C++ fully supports  (73)  programming.

(73)

● 某主机的 IP地址为 10.100.100.01/20，其子网掩码是 （70） 。

（70）

● The line of computing jobs waiting to be run on a computer system might be a  (71) . The jobs are serviced in the order of their arrival, that is, the first in is the first out.

   (71)

● 在 Outlook 中，通常借助 （68） 来传送一个文件。

（68）

● 在检测网络故障时使用的 ping 命令是基于 （67） 协议实现的。

（67）

● 在 TCP/IP 传输层的段（segment）中，采用（66） 来区分不同的应用进程。

（66）

● 设任意多面体的顶点数为 V，边数为 E，面数为 F。请根据实例判断并选出正确反映这三者之间关系的公式 (65) 。

（65）