更多"Mobile phones
What Are Mobile Phon"的相关试题:
[单项选择] Mobile phones
What Are Mobile Phones
A mobile phone, also known as a cellphone or cellular phone, is a portable electronic device which behaves as a normal telephone whilst being able to move over a wide area (compare cordless phone which acts as a telephone only within a limited range). Cellphones allow connections to be made to the telephone network, normally by directly dialing the other party’’s number on an inbuilt keypad. Most current cellphones use a combination of radio wave transmission and conventional telephone circuit switching, though packet switching is already in use for some parts of the cellphone network, especially for services such as Internet access and WAP.
Some of the world’’s largest cellphone manufacturers include Alcatel, Audiovox, Kyocera (formerly the handset division of Qualcomm), LG, Motorola, Nokia, Panasonic (Matsushita Electric), Philips, Sagem, Samsung, Sanyo, Siemens, SK Teletech, and Sony Ericsson.
A. Y
B. N
C. NG