有哪些因素影响小企业主的对于风险的态度？
电力网的有功负荷用大于供，主要影响到（）。 ["电网电压下降；","频率下降；","电压波形畸变；","三相电压失衡"]
You have enabled backup optimization in RMAN. You issue the following RMAN command to configure a redundancy-based retention policy: CONFIGURE RETENTION POLICY TO REDUNDANCY 3; Which statement is true?（） [" The command fails because you cannot configure a redundancy-based retention policy when backup optimization is enabled"," Backup optimization is performed, but RMAN considers the redundancy-based retention policy when it determines which datafiles should be backed up"," Backup optimization is permanently disabled"," Backup optimization is temporarily disabled because a redundancy-based retention policy is specified"]
小企业与大企业相比较有哪些独特之处？
什么是有效？
什么是小企业？它有哪些基本特点？
