制冷压缩机发生液击时首先是假盖顶起。
参考答案：对
---Was it midnight_____ the heartbreaking news came_____ he passed away?
---I am afraid so.
A．that, that
B．that, when
C．when, that
D．when, which
机械设备的试运转应遵循的原则上什么？
