受挫后的建设性行为主要有（） ["升华","坚持","替代","补偿","折中"]
用于压力级别比较高的容器，应选用（）。 ["对焊法兰","甲型平焊法兰","乙型平焊法兰"]
客户生命周期由哪些阶段组成？各阶段的特点是什么？
（）是个体由经验引起的相对持久的心理和行为的变化。 ["适应","发展","学习","表现"]
What should you look at first to compute the number of undo blocks written per second to disk？ （） ["V$UNDOSTAT","V$TRANSACTION","V$ROLLSTAT","DBA_UNDO_EXTENTS","DBA_ROLLBACK_SEGS"]
丙烷压缩辅冷系统的工作原理及组成。
