Bluetooth is a universal radio interface in the (71) frequency hand that enables portable electronic devices to connect and communicate wirelessly via short-range, ad hoc networks. Each unit can simultaneously communicate with up to (72) other units per piconet. Moreover, each unit can simultaneously (73) to several piconets. Eliminates the need for wires, cables and connectors for and between cordless or mobile phones, modems, headsets, PDAs, Computers, printers, projectors, local area networks, and so on, and paves the way for new and completely different devices and applications. Technology Characteristics (74) symbol rate exploits maximum available (75) bandwidth。

A．conformance

B．relate

C．belong

D．secrecy

欧洲文艺复兴运动的实质是( )

A．希腊、罗马古典文化的复兴

B．封建文化的复兴

C．资产阶级文化革命运动

D．现代文化的兴起