关于软件生命周期,下列哪个说法是不正确的?()
A. 软件生命周期分为计划、开发和运行三个阶段
B. 在计划阶段要进行问题定义和需求分析
C. 在开发后期要进行编写代码和软件测试
D. 在运行阶段主要是进行软件维护
5.In many schools we employ computers for schoolchildren to learn how to use them.
A PC can be a laptop or a desktop.
A CPU, usually regarded as the heart of a computer, can be a microprocessor.