单项选择题
A. All the devices and parts are put in the basement. B. All the devices and parts are put into a single box. C. Cellular phone and Internet are part of this system.
A. How to control the growing number of intranet users. B. How to prevent teenagers in town from chatting on the Web. C. How to keep some information secret and accessible only to qualified people.
A． At a very steady speed. B． At a very rapid speed. C． At a very slow speed.