Microwave communication uses high-frequency (1)______ waves that travel in straightlines throughthe air. Because the waves cann

admin2013-01-05 31

问题 Microwave communication uses high-frequency (1)______ waves that travel in straightlines throughthe air. Because the waves cannot (2)______with the curvature of the earth, they can be (3)_____only over short distance. Thus, microwave is a good (4) ______for sendingdata between buildings ina city or on a large college campus. For longer distances, the wavesmust be relayed by means of"dishes" or (5)_____. These can be installed on towers, highbuildings, and mountain tops.
(1)______
A．optical
B．radio
C．electrical
D．Magnetic

选项 A、
B、
C、
D、

答案B

解析

转载请注明原文地址:https://kaotiyun.com/show/YWkZ777K

本试题收录于：网络管理员上午基础知识考试题库软考初级分类