题目内容

Jack Alva was not a good student at school and he ___1_____ often ____2_____ by his teacher. However, he had a small chemistry laboratory at home. When he was doing an experiment in his lab, he ___3_______ in his experiment, and was often ____4______ of what was happening around him. ____5______ being interested in chemistry, he also became good at electrical engineering.

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微机系统中若用4片8259A构成主、从两级中断控制逻辑,接至CPU的可屏蔽中断请求线INTR上,最多可扩展为( )级外部硬中断。

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B. 程序查询方式
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简述中断处理过程?

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