问题
单项选择题
In recent years, TCP/IP has also begun to be used by telephone companies to provide faster, cheaper telephone (67)
A. transmitting
B. transmited
C. transfers
D. transmissions
答案
参考答案：D
解析： 最近几年，TCP/IP 已经被电信公司使用为用户提供更快速、更廉价的电话通信。