MIMD systems can be classified into (71) -oriented systems, high-availability systems and response-oriented systems. The goal of (71) . oriented multiprocessing is to obtain high (71) (72) minimal computing cost. The techniques employed by multiprocessor operating systems to achieve this goal take advantage of an inherent processing versus input/output balance in the workload to produce (73) and (74) loading of system (75) .

（72）处填（）。

A．at

B．of

C．on

D．to

240÷59≈3。[ ]