单项选择题
A.well ventilated B.well clean C.in good order D.more room
It is well known that good lubrication will （） the bear...
单项选择题It is well known that good lubrication will （） the bearings from becoming overheated.
A.present B.prevent C.avoid D.provide
It is very necessary that each cylinder （） before the c...
单项选择题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
A.is scavenged B.is atomized with fuel oil C.be scavenged D.be atomized with fuel oil
