绘出Stribeck曲线，标明不同摩擦状态的三个区域，并说明各个区域影响摩擦的主要因素。
（）体现商品与货币的等价交换的转移过程。 物流。 信息流。 资金流。 商流。
If it is properly deployed， a controller-based access point is capable of monitoring all VLANs on anetwork when you select which of the following modes from the AP Mode drop-down menu onthe controller？（） Monitor。 Rogue Detector。 Sniffer。 Mirror。
What are three benefits of performing data definition language （DDL） statements against a partitioned table with the UPDATE GLOBAL INDEXES clause？（） Global indexes are rebuilt automatically at the end of the DDL operation thereby avoiding problems with the UNUSABLE status. 。 You do not have to search for invalid global indexes after the DDL command completes and rebuild them individually. 。 Global indexes are maintained during the operation of the DDL command and therefore can be used by any concurrent query. 。 Global indexes remain intact and available for use by data manipulation language （DML） statements even for sessions that have not enabled the skipping of unusable indexes.。
ESDSYSTEM的目的是什么？
下列关于后除极的叙述，哪项是正确的（）
