在Windows操作系统中，关于应用程序窗口的描述不正确的是(1)。当桌面上有多个窗口时，这些窗口(2)；指定活动窗口的正确方法是(3)。

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.

(70)

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