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刷刷题刷刷变学霸
举一反三
【单选题】第二篇 Sleep We all know that the normal human daily cycle of activity is of some 7 - 8 hours’ sleep alternating with some 16 - 17 hours’ wakefulness and that, broadly speaking, the sleep n...
A.
people hate the inconvenience of working on night shifts.
B.
your life is disturbed by changing from day to night routines and back.
C.
not all industries work at the same hours.
D.
it is difficult to find a corps of good night workers.
【单选题】下列有关分离工艺机床使用技术安全操作规程的说法正确的是（）
A.
操作前要做好一切劳动保护工作
B.
检查机床周围有无障碍物，要确保工作地整洁有序
C.
试车：在确认机床情况正常后才能启动运转，观察有无异常现象
D.
机床未在润滑良好的情况下也可操作