A program can use a device if that hardware is unavailable.
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Operating system sets up a directory of programs undergoing execution and the devices.
A. 对
B. 错
Error recovery does not belong to operating system.
A. 对
B. 错
One of the five functions of an operating system is memory management.
A. 对
B. 错
Many operating systems have not similar characteristics.
A. 对
B. 错
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