活塞式压缩机的缺点是什么?
参考答案:
(1)活塞式压缩机因活塞作直线往复运动,产生惯性力致使转速受到限制。
(2)易损件多;
(3)运转时有振动输气不连续,气体压力有脉动
—Must I get up early tomorrow morning?
—No, _ .[ ]
A. you mustn't
B. I don't think you have to
C. you can't
D. you need
某尿毒症患者,自诉极度疲乏、胸闷、心慌、尿少,体检心律不齐,期前收缩8—10次/分,测血钾8.8mmol/L。若不紧急处理,会突然发生
A.休克
B.昏迷
C.心脏停搏
D.呼吸衰竭
E.心力衰竭