单选题 ______ is the sending and receiving of the messages by computer. It is afast, low-cost way of communicating worldwide.
   A．LAN    B．Post office    C．E-Mail    D．Interface
【正确答案】 C
【答案解析】由sending and receiving ofthe messages推断答案是C。
   [参考译文]电子邮件是通过计算机接收和发送的信息。它是在世界范围内快速、低成本的通信方法。