Circuit-switching technology is used in Publish Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and code Division Multiple Access (CMDA) . It is a ( ) information transfer mode.

  • A connection oriented
  • B connectionless
  • C high bandwidth utilization
  • Dpoor real-time
参考答案: A
解题思路: 电路交换技术用户PSTN、GSM和CDMA,它采用的是面向连接的通信方式。