控制设备的二次回路绝缘电阻应大于（）。
A.0.5MΩ
B.1MΩ
C.10MΩ
D.20MΩ
参考答案：B
In relation to the Labour Contract Law of China:
(b) state the legal relations between the entity despatching labour services and the persons despatched to the labour service purchaser; (2 marks)
闪蒸槽的压力（）控制。
A.PV63506
B.PV63507
C.PV63508
