依树木的主要经济用途分类
You find this query being used in your Oracle 12c database: Which method a used by the optimizer to limit the rows being returned?（） A filter is added to the table query dynamically using ROWNUM to limit the rows to 20 percent of the total rows。 All the rows are returned to the client or middle tier but only the first 20 percent are returned to the screen or the application.。 A view is created during execution and a filter on the view limits the rows to 20 percent of the total rows.。 A TOP-N query is created to limit the rows to 20 percent of the total row。
You enabled the flashback logging feature， but you have not specified the location of the flash recovery area. Which location would be used as the default location for the flash recovery area？（） The location used for control files.。 The location used for redo log files.。 The location set by using $ORACLE_BASE。 The location set by using $ORACLE_HOME。 The location set by using CORE_DUMP_DEST。 The location set by using BACKGROUND_DUMP_DEST。
贡献原则
粘性土的等效摩擦角是（） 根据有效应力原理来计算的。 将滑动面上的法向应力折算为内摩擦角。 根据静力平衡原理来计算的。 根据抗剪强度相等原理来计算的。
幼儿上课时不专心的行为属于（）
