在行为科学理论中侧重研究人的需要、动机和激励问题的理论是（） 人性管理理论。 群体行为理论。 人类需要理论。 领导行为理论。
采集水中挥发性有机物和汞样品时，采样容器应如何洗涤?
You work in a company which uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 instance. There is a database named named Dworks in the instance. The Dworks table has a table named BillDetails which has a clustered primary key named BillId on the BillId column. The BillDetails table has a single XML column named GoodsDetails. The XML column has an XML index and XML data are stored in this XML column. A new column named GoodsID is added to the BillDetails table. GoodsID must be included in the primary key. So what action should you perform to achieve this goal？（） You should drop the XML index on the table. Modify the primary key. Recreate the XML index 。 You should alter the XML index and set the ALLOW_ROW_LOCKS = OFF option. Alter the primary key and set the ALLOW_ROW_LOCKS = ON option. 。 You should move the XML data to a temporary table. Clear the XML data from the original table by setting the GoodsDetails column to NULL. Modify the primary key. Repopulate the ProductSpecs column. 。 You should disable the XML index on the GoodsDetails column. Modify the primary key.Enable the XML index on the ProductSpecs column.。
表示品质的方法的分类可归纳为（）。 凭样品表示商品的品质。 凭产地表示商品的品质。 凭规格表示商品的品质。 凭商标表示商品的品质。
四呼
系统设计阶段的最后一项工作是编写（）。
