齿轮泵产生噪音的原因?
参考答案:
(1)吸口进入空气;
(2)吸口真空度过高;
(3)安全阀跳动大;
(4)泵轴弯曲或轴承间隙过大;
(5)泵与原动机不对中。
---He_____ attend at the meeting.
--- But in fact he didn’t come.
A. is suppose to B. was suppose to C. was supposed to
长时间较高的呼吸末正压通气(PEEP)可能的并发症和副作用,不包括下列哪项()。
A.肺泡破裂、气胸
B.降低心排血量,影响肾、肝功能
C.颅内压增高,加重脑水肿
D.增加静脉回流,加重心脏前负荷
E.增加应力和牵张力超负荷,加重肺损伤