信号机制是解决进程同步和互斥的有效工具。实现进程间的互斥时，公用变量信号的初值一般设置为(18)；实现进程间的同步时，私用变量初值一般设置为(19)。

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When you open a file or run a program in a computer, a window appears on the desktop of your computer. The(67)of the window indicates which program you are currently working in arid its color will become blue if a window is active. When you click on The(68), the window disappears and appears as a button on the taskbar. Clicking on a button in(69)will invoke a specific command.

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A(66)holds enough bits to store a single character while a(67)is a group of bytes.

The HTML is the language used to create(73)for use on the WWW.

Voice-(72)technology converts human speech into a digital code that a computer can under- stand.

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