膨胀机的启动条件是什么?
参考答案:
膨胀机启动时,增压机和膨胀机密封气必须大于0.2MPa时才允许启动膨胀机油泵,润滑油压力大于0.4MPa时才能允许启动膨胀机。
Tom looked at Jenny, with tears______his eyes, and shouted out the words_______in his heart for years.[ ]
A. filling; having been hidden
B. filled; hidden
C. filling; hidden
D. filled; hiding
穿()、瘦型鞋的人,脚趾容易受到挤压,血液循环不畅,容易引起趾甲变形。
A.平底鞋
B.高跟鞋
C.拖鞋
D.布鞋