Which two statements about subqueries are true? （） A subquery should retrieve only one row.。 A subquery can retrieve zero or more rows.。 A subquery can be used only in SQL query statements.。 Subqueries CANNOT be nested by more than two levels.。 A subquery CANNOT be used in an SQL query statement that uses group functions.。 When a subquery is used with an inequality comparison operator in the outer SQL statement, the column list in the SELECT clause of the subquery should contain only one column.。
工程质量管理的重点应以（）为主。 预防.改正。 事后检查把关。 经济处罚。 行政处罚。
What must an administrator do to create two new volume groups on a system with only one spare disk？（） Run the ‘mkvg -M’ command to create multiple volume groups on a single disk。 Add a new disk to the system or release a disk from the one of the existing volume groups。 Run the ‘mkvg’ command to create multiple volume groups on a single disk providing the disk does not have a PVID。 Run the ‘mkvg’ command to create multiple volume groups on a single disk providing the volume groups have the same PP size。
What is required for the minimum configuration of the TS7650 ProtecTIER Appliance console? （） 50 MB of available disk space and 128 MB of RAM。 100 MB of available disk space and 256 MB of RAM。 200 MB of available disk space and 512 MB of RAM。 300 MB of available disk space and 512 MB of RAM。
同一带铁芯的线圈分别接到电压相同的直流电路和交流电路中，这时会（）。 接入直流电路的电流强。 接入交流电路的电流强。 两种情况相同。
下列内容中，商业计划书与项目可行性报告共同涉及的问题是（）。
