单选题

A ______consists of the symbols, characters, and usage rules that permit people to communicate with computer.

单选题 One of the greatest features of a home______is the ability to share on Internet connection simultaneously over two or more computers.

单选题 The _______in E-mail message has affected almost every computer around the world and has cause the damage of up to US$1 billion in North America.

单选题 A ______is a function unit that interprets and carries out instructions.

单选题 Insufficient ______can cause a processor to work at 50% or even more below its performance potential.

单选题 Most_____measure involve data encryption and password.

单选题 One of the basic rules of computer security is change your ______ regularly

单选题 In_____ ,the only element that can be deleted or removed is the one that was inserted most recently

单选题 ______Software, also called end-user program, includes data base programs ,word processors, spread sheets etc.