泵效
参考答案：
抽油泵的实际排量与理论排量的比值。
肝硬化大量放腹水时，易于诱发（）。
A.晕厥
B.肝昏迷
C.上消化道出血
D.休克
E.呼吸衰竭
Some parents are just too protective. They want to ______ their kids from every kind of danger, real or imagined.
A．escape
B．educate
C．shelter
D．persuade
