所谓“变号操作”是指将一个整数变成绝对值相同但符号相反的另一个整数。假设使用补码表示的8位整数X=10010101，则经过变号操作后结果为( )。

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NET is both a business strategy from Microsoft and its(71)of(72)support for what are known as Web services, the ability to use the Web rather than your own computer for various services. Microsoft's goal is to provide individual and business users with a(73)interoperable and Web-enabled interface for applications and computing devices and to make computing activities increasingly Web browser-oriented. The .NET(74)includes servers; building-block services, such as Web-based data storage; and device software. It also includes Passport, Microsoft's fill-in-the-form-only-once identity(75)service.

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操作系统是一种系统软件，它有许多种类，PC-DOS是一种(12)操作系统， Windows是具有图形界面的(13)运行方式的操作系统。(14)是在体系结构上采用了客户机服务器模式的网络操作系统。

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