你如何理解OpenDialog（打开文件对话框）和SaveDialog（保存文件对话框）这两个组件的基本功能？它们负责文件的打开和保存吗？
简述轴与孔的热胀配合法。
Which three statements describe the functionality of the DO_KEY built-in?（） ["It accepts both a built-in and a key name as argument. ","If no key trigger is defined, the specified built-in executes. ","Its parameter must be specified in upper case, enclosed in single quotation marks. ","It performs the same task as if you pressed the function key associated with the specified argument. ","It executes the key trigger that corresponds to the built-in specified as its parameter.&e"]
When performing a backup using Recovery Manager （RMAN）， which four types of files can be backed up with the RMAN BACKUPcommand？ （） [" data file"," password file"," archivelog file"," temporary file"," online redo log file"," the current control file"," the tnsnames.ora file"," current server parameter file"]
消费者在购物环境中所表现出的消费行为，即（）是消费者行为的重要环节。 ["购买行为","消费过程","购买过程","销售过程"]
“礼”在先秦时期的发展大致经过了三个阶段，其中第一阶段是作为（）的阶段；第二阶段是指（）的阶段，第三阶段是指（）。
