单项选择题 You have a Microsoft Internet Security and Accelerator （ISA） 2006 server that provides all Internet accessfor your company.  You have two Mailbox servers configured in a database availability group （DAG）， two Client Accessservers， and two Hub Transport servers.  You need to recommend changes to the environment to ensure that users can access Outlook Web App（OWA） from the Internet if any single server fails.  What should you recommend？（）

单项选择题 Your company has 10 offices.  The offices connect to the Internet by using a WAN link.  The offices connect to each other by using a VPN connection.  An Active Directory site exists for each office. You plan to deploy Exchange Server 2010. Each site will contain two Exchange Server 2010 servers.  You need to recommend the placement of domain controllers and global catalog servers to meet thefollowing requirements： .Minimize the number of domain controllers .Must be able to deliver e-mail messages between users of the same office， if a domain controller and a WAN link fail simultaneously What should you recommend？（）

单项选择题 You have an Exchange Server 2010 organization that contains two Hub Transport servers.  You need to design a recovery plan for the Hub Transport servers that meets the following requirements： .Restores all Windows settings .Restores all Exchange configurations.Minimizes administrative effort What should you include in the plan？（）