在信用证支付方式下，象征性交货意指卖方的交货义务是（）。 ["不交货","仅交单","凭单交货","实际性交货"]
You are the Exchange administrator for the Xxx Corporation’s Exchange 2010 organization.All servers in the forest must have anti-virus software that contains a file level virus scanner.After you implement the antivirus software， several users report that they cannot access their mailbox.What should you do？（） ["Restart the Microsoft Exchange Mail Submission service","Run the ESEUTIL utility on the Exchange databases","Exclude *.edb and *.log files from the virus scanner","Restart the Microsoft Exchange Transport service","Restart the Microsoft Exchange Information Store service"]
某企业1994年度利润总额为116，000元，资产总额期初为1017，450元，其末数为1208，650元；该年度企业实收资本为750，000元；年度销售收入为396，000元，年度销售成本为250，000元，销售费用6，5000元，销售税金及附加6，600元，管理费用8，000元，财务费用8，900元；年度所有者权益年初数793，365元，年末数为814，050元。权益报酬率
设备维修保养制度制定的意义是（）。 ["发现厂内机动车辆制造时缺陷","主要是解决厂内机动车辆安装时的一些缺陷","提高设备的完好率","有效地防止违章操作"]
在定时库存控制模型中，每次订货的订货批量（） ["保持固定不变","随着自上次订货以来物品的使用率的变化而变化","随着订货周期发生变化","随着订货点发生变化"]
固定化细胞发酵产酶有哪些特点？
