变压器短路实验常在高压侧进行,其原因是()。 ["高压侧电流较小,便于测量","低压侧电流太大,变压器易于过电流损坏","可以使低压侧电流小一点","变压器发热可以小一些"]
You executed this command to create a temporary table: SQL> CREATE GLOBAL TEMPORARY TABLE report_work_area (startdate DATE, enddate DATE, class CHAR(20))ON COMMIT PRESERVE ROWS; Which statement is true about the rows inserted into the REPORT_WORK_AREA table during atransaction () ["The rows stay in the table only until session termination.","The rows stay in the table only until the next transaction starts on the table.","The rows are visible to all current sessions after the transaction is committed.","The rows stay available for subsequent sessions after the transaction is committed"]
设计单位不应当考虑施工安全操作和防护的需要,对涉及施工安全的重点部位和环节在设计文件中注明,并对防范生产安全事故提出指导意见。
往复式对称平衡型压缩机,相对两列气缸的曲柄错角为()。 ["60°","90°","120°","180°"]
When creating a SQL tuning set,which of the following steps allows the DBA to reduce the size of the SQL set by selecting specific operators and values?() [" Filter versions"," Filter loads"," Filter tasks"," Filter optio"]
锅炉排污的目的是(),排污的方式有()、()。