辅助存储设备可以加大内存容量。
考虑到目前内存的价格，交换空间是一种非常缓慢的辅助存储器。
With current memory prices, swap space represents a very slow secondary memory.
指令和数据在计算机的内存中一时用不到的话，就要用辅助存储单元来对它们进行保存。
Auxiliary storage units are used to store instructions and date when they are not being used in main memory of the computer.
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