Which of the following is a characteristic of a schema?（） Foreign key references cannot cross schema boundaries.。 A DB2 user must be created before a schema with the same name can be created.。 If no schema is specified when an object is created, the default schema PUBLIC is used.。 A schema enables the creation of multiple objects in a database without encountering namespace collisions.。
PHB
社会制度的构成包括（）。 文化体系。 宗教体系。 规范体系。 社会机构与设施。
下面4种路由中，哪一种路由的子网掩码是255.255.255.255？（）。 远程网络路由。 主机路由。 默认路由。 静态路由。
Company.com recently updated the programs used in an HACMP pre-event. The procedure Involved coping the new code over the old code in the appropriate directory on one of the nodes as indicated by the HACMP event entry. The cluster was synchronized. During a fallover test， the backup system did not behave as expected. What is the most likely problem？（） The new pre-event program was node locked to a hostname。 The new pre-event program was not made executable on al nodes.。 The new pre-event program was not compatible with the backup machine.。 The new pre-event program was not propagated to all the nodes in the cluster.。
在企业经济活动中，其固定总成本的数额随产量的变化而（）。
