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

单项选择题 某主机的IP 地址为 10.100.100.01/20，其子网掩码是（）。

单项选择题 在Windows Server2003 操作系统中可以通过安装（）组件创建 FTP 站点。