个人计算机中的数字声音有两种不同的表示方法：一种是(53)，它通过对实际声音的波形信号进行数字化(取样和量化)而获得，它能高保真地表示现实世界中任何客观存在的真实声音；另一种是使用符号对声音进行描述，然后通过合成的方法生成声音。用符号描述的乐器演奏的音乐声音(54)属于上述第二类声音，它所使用的音乐合成器有(55)。

Viruses usually have two phases to their execution, the infection phase and the(75)phase. The later phase is optional, since stone viruses simply reproduce.

(74)isn't a type of transmission medium used for LANs.

A(73)is used to communicate with another computer over telephone lines.

Multimedia is the combination of computer and(72)technology.

In the RGB color spaces, each pixel on the screen has a corresponding RGB value which consists of()components.

In C language,(70)is a collection of one or more variables, possibly of different types, grouped together under a single name for convenient handling.

A stack protocol can be used for(69).

A(68)program is usually described as a program written in high-level language.

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