单项选择题 Your network contains an internal network and a perimeter network. The internal network contains a single Active Directory site.  The perimeter network contains two Exchange Server 2010 Edge Transport servers. You plan to deploy an Exchange Server 2010 organization on the internal network.  You need to plan the deployment of Hub Transport server roles to meet the following requirements：.If a single Hub Transport server fails， e-mail messages from the Internet must be delivered to the Mailboxservers. .If a single Hub Transport server fails， users must be able to send e-mail messages to other users thathave mailboxes on the same Mailbox server.  What should you include in the plan？（）

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 aWAN link fail simultaneously What should you recommend？（）