机械密封因压盖松动而使密封面移动时可以不更换动、静环。
下列属于市场竞争行为的主要有（） ["A.定价行为 ","B.扩张行为 ","C.广告行为 ","D.兼并行为 ","E.促销行为"]
根据《社会保险法》规定，工会依法维护职工的合法权益，有权参与社会保险重大事项的研究，参加社会保险监督委员会，对与职工社会保险权益有关的事项进行监督。
产生肌力最大的肌收缩形式是（） ["向心性收缩","离心性收缩","等长收缩","静力收缩","动力性收缩"]
The database is configured in ARCHIVELOG mode and regular complete database backups are taken. The loss of which two types of files may require a recovery with the RESETLOGS option？（） [" Control files"," Password files"," Inactive online redo log file"," Archived log files required to perform recovery"," Newly created tablespace which is not backed u"]
保护环境
