介质中质点产生相应的横向和纵向两种振动的合成,使质点作()的振动和传播叫兰姆波。
A.直线轨迹
B.半圆轨迹
C.椭圆轨迹
D.三角轨迹
参考答案:C
Circuit-switching technology is used in Public Switched Telephone Network (PSTN), Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). It is a()information transfer mode.
A.connection oriented
B.connectionless
C.high bandwidth utilization
D.poor real-time
速汇通业务的办理渠道包括()
A、营业柜台
B、自助终端
C、电话银行
D、网上银行