单项选择题 You work as an Exchange Administrator for Xxx Inc.The company has a Windows 2008 Active Directorybased network.The network contains an Exchange Server 2010 organization.There are 150 mailboxes in the messaging organization， which are stored in a mailbox database named  MailboxDatabase.You have set the storage quota limit to 200 MB for all mailboxes in the database MailboxDatabase.When the limit of a mailbox reaches 180 MB， the corresponding user gets a warning message.After reaching the limit， the users are not able to send and receive any e-mail.The manager of your company， John Smith， asks you to change the storage limit for his mailbox to 280 MB. Which of the following commands will you enter in the Exchange Management Shell to accomplish the task？（）

单项选择题 You have an Exchange Server 2010 server named Server1. Server1 hosts a mailbox database named DB1 that contains 25 user mailboxes. You create a new public folder database named PUB2. You need to configure PUB2 as the default public folder database for each mailbox on DB1.  Which properties should you modify（）？

单项选择题 Your company has a main office and a branch office. The branch office administrators are the only members of a custom management role group. The role group is configured to allow members to manage recipients. You notice that the branch office administrators can manage recipients in both offices. You need to ensure that the branch office administrators can manage recipients in the branch office only.  What should you do()？