单项选择题 在计算机系统中常用的输入/输出方式有无条件传送、中断、程序查询和DMA等，采用（）方式，数据在传输过程中不需要CPU参与工作。

单项选择题 One of the greatest features of a home （）is the ability to share one Internet connection simultaneously over two or more computers.

单项选择题 Insufficient （） can cause a processor to work at 50% or even more below its performance potential.