力沿其作用线移到刚体的另一点后，它对刚体的作用效果将发生变化。
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道路货物运输经营者应当加强对从业人员的（），确保道路运输安全。
A. 安全教育
B. 专业技能教育
C. 职业道德教育
D. 素质教育
Two data files have been deleted at the operating system level by accident. Your database is running in ARCHIVELOG mode and online backups are taken nightly. One of the data files that has been deleted belongs to the USERS tablespace on the other belongs to the SYSTEM tablespace. How can you recover from this situation？（）
A. Shut down the database, restore the two data files and then start up the database.
B. Take the system and users tablespace offline, restore the two data files, recover the two datafiles, and then bring the SYSTEM and USERS tablespaces online.
C. Shut down the database, restore the two data files, start up the database in MOUNT mode, recover the two data files, and then alter the database open.
D. Take the SYSTEM and USERS tablespaces offline, recover the two datafiles and then bring the SYSTEM and USERS tablespaces online.
市场汇率存在的前提是（）
A. 货币能自由兑换
B. 货币不能自由兑换
C. 外汇管制严格
D. 外汇管制较松
现代广告广义策划阶段主要有分析阶段、规划阶段、（）和控制阶段。
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