离心式压缩机油润滑的目的,下列叙述不正确的是()。
A、变干摩擦为液体摩擦
B、降低磨损速度
C、减轻摩擦
D、提高气体压力
参考答案:D
Some passers-by witnessed the car accident____ five passengers were killed, a baby included.
A.that
B.which
C.in which
D.in that
金属发兰垫片(1Cr18Ni9Ti)可用于工作温度不大于()的法兰上。