Before a marine diesel engine is started the cylinders and pistons must be ().
时间:2020-08-14 02:02:28 关键词:engine,is,startedBefore a marine diesel engine is started the cylinders and pistons must be ().
A.cooled to appropriate temperature
B.warmed up gradually to appropriate temperature
C.opened up and renewed
D.ground and polished
答案解析
B
举一反三