2. a process may be broken up into pieces that do not need to located contiguously in main memory during execution. 进程可以划分成许多块(页和段),在执行过 程中,这些块不需要连续地位于主存中)2. A process may be broken up into pieces that do not need to located contiguously in main memory during execution. (一个 进程可以划分成许多块（页和段），在执行过 程中，这些块不需要连续地位于主存中 )