实测的调速器静特性曲线在转速上升和下降时不是一条曲线，而是两条曲线，往返两条曲线之间的部分叫做（）。
参考答案：转速死区
— I really don't understand why he treats his parents in that way.
— ______. [ ]
A. It's a small world
B. It takes all sorts
C. It doesn't matter
D. It doesn't make sense
观察胸腔闭式引流管引流血性液每小时 200ml，并有血块溢出，应采取的治疗措施
A．大量输血
B．快速补液
C．剖胸探查
D．继续观察
E．以上均不对
