It is very necessary that each cylinder () before the charged air is compressed.
A. is scavenged
B. has been scavenged
C. be scavenged
D. was scavenged
下列选项中,可作为汽车制动效能评价指标的是()。
A. 制动距离
B. 制动释放时间
C. 制动器起作用时间
D. 制动协调时间
气分证形成的途径为(1)(),(2)(),(3)(),(4)()。
什么是主生产计划冻结期?如何看待主生产计划冻结期的设置?