按照《公路养护安全作业规程》（JTGH30）从事长大桥隧检查、养护作业的单位和人员，必须遵守下列规定。（）
A. 作业人员必须穿着统一的安全标志服
B. 作业现场必须设臵规范的施工作业标志和安全防护设施
C. 作业车辆和机械必须开启示警灯，并按规范设臵作业标志
D. 养护物料应当堆放在作业区内，作业完毕后应当及时清除遗留物
E. 养护人员上路作业要注意交通安全，不得在作业区外活动
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按照国家免疫规划疫苗的免疫程序规定，基础免疫疫苗必须按月接种，而加强免疫可以根据情况按每半年或一年接种一次。
A. 正确
B. 错误
整理最主要是针对空间不被浪费。
A. 正确
B. 错误
汽车巡航控制状态下行驶，当车速低于（）时，该系统自动取消巡航控制，使汽车在制动、转弯时，巡航控制不起作用，以确保行车安全。
A. 40km/h
B. 60km/h
C. 80km/h
D. 100km/h
Your database is in NOARCHIVELOG mode. You start to do a backup， but your users complain that they dont want you to shut down the database to perform the backup. What options are available to you？（）
A. Put the database in hot backup mode and perform an online backup，including backing up the archived redo logs.
B. Just back up the database datafiles without shutting down the database.
C. You will have to wait until you can shut down the database to perform the backup.
D. Mark each datafile as backup in progress， back them up individually，and then mark them as backup not in progress. No archived redo logs will need to be backed up.
E. Only back up the datafiles that the user will not be touching. Once the user has finished what they were doing，you can shut down the database and back up the datafiles the user changed during the course of the remaining backu
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