简述双水相萃取的概念与特点。
库存盘点的方法：主要有（）和定期盘点两种方法。
You have a portable computer that runs Windows XP Professional. The computer supports Advanced Configuration and Power Interface (ACPI). You need to ensure that the computer enters Sleep Mode when you close the lid of the computer. What should you do?（） ["From Control Panel, configure the Power Options. ","From the System properties, configure the Data Execution Prevention settings. ","From the Services console, set the Startup type for the Human Interface Devices service to Manual.","From the Services console, set the Startup type for the Uninterruptable Power Supply service to Manual.&e"]
Your company has a server named FS1. FS1 hosts the domain-based DFS namespace named \\contoso. com\dfs all domain users store their data in subfolders within the DFS namespace. You need to prevent all users except administrators， from creating new folders or new files at the root of the \\contoso.com\dfs share. What should you do（）？ ["Run the dnscmd.exe \\\\FS1\\dfs \/restore command on FS1","Configure the NTFS permissions for the C：\\DFSroots\\dfs folder on FS1. Set the create folders\/append data special permission to Deny for the Authenticated Users group. Set the full control permission to allow for the administrators group","Start the delegate management permissions wizard for the dfs namespace named \\\\contoso.com\\dfs remove all groups that have the permission type explicit except the administrators group","Configure the \\\\fs1\\dfs shared folder permissions. Set the permissions for the authenticated users group to reader. set the permissions for the administrations group to co-owner."]
不得用于消防给水系统的塑料管道是（）。 ["PB管","PEX管","PP—R管","PVC—C管"]
信息传递是信息资源价值得以实现的重要条件，它是指以（）为起点，通过（）或者（），将信息资源传递给信息接收者的过程。
