作为调度端AGC控制系统,当正确接收到电厂的()应该能够保证指令不在在电厂全厂振动区内长时间停留。
A. 全厂调节上、下限值
B. 全厂振动区上、下限值
C. 全厂振动区上限值
D. 全厂振动区下限值
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阀门渗漏故障处理完毕后,必须检查泄漏情况。
A. 正确
B. 错误
Your database operates in ARCHIVELOG mode. The redo log files are not multiplexed and one of the online redo logs is missing. The missing redo log sequence, 230, is not archived, and it contained information from 10:35 a.m. onwards. The current time is 11:00 a.m. Because of a disk crash, you executed the following command to perform an incomplete recovery: RMAN> RUN { 2> SET UNTIL SEQUENCE 230 THREAD 1; 3> ALTER DATABASE MOUNT; 4> RESTORE DATABASE; 5> RECOVER DATABASE; 6> ALTER DATABASE OPEN RESETLOGS; 7> }; With reference to this scenario, which statement is true?()
A. RMAN recovers up to log sequence 230, but not including 230.
B. RMAN returns an error because the log sequence number mentioned in the command should be 229.
C. RMAN returns an error because the log sequence number mentioned in the command may never be missing.
D. RMAN recovers up to and including log sequence 229 but then returns an error because log sequence 230 is missing.