开孔作业中，若频繁发生卡刀，最可能的原因是（） 鞍形板在管线上松动。 震动使刀具结合器与内丝头杆连接松动。 管线存在硬点。 刀齿钝化。
促使人实现社会化的最有效形式是（） 社会实践。 观察模仿。 做中学。 教育。
按照《消费者权益保护法》的规定，保护消费者的合法权益是（） 商家的责任。 政府的责任。 中国消费者协会的责任。 全社会共同的责任。
Examine the following RMAN script： RMAN> run { debug on； allocate channel c1 type disk； backup datafile 5； } Which statement describes the purpose of the script？（） The data file is checked for physical corruption and backed up if found clean.。 The backup of data file 5 is performed and the interactive messages during the backup are suppressed.。 The existing backup for the data file is checked and the backup is performed if there are changes in the data file after the last backup.。 The backup of data file 5 is performed and all SQL statements that are executed during RMAN compilation and their results are displayed。
The nice value is 60 in the ps listing. Which command is used to change this to a value of 20？（） renice -n -20 {PID}。 renice -n 20 {PID}。 renice -n -40 {PID}。 renice -n 40 {PID}。
Where are timekeeping services configured？（）
