It is necessary for us () after having served for a certain period.
A. to change the lube oil
B. have the lube oil purified
C. have the lube oil burnt
D. to analyze the lube oil
请父母帮助照看孩子,每月给父母1000元如何记账?
在市场经济条件下,树立组织信誉已成为公共关系的重要任务之一。
A. 正确
B. 错误
主传动机构齿轮,轴承的润滑方式是怎样的?如何检查隙润滑状况?