单项选择题 Your company has a main office and 10 branch offices. Each office connects to the Internet by using a direct link.  The main office connects to the branch offices by using a WAN link. You plan to deploy Exchange Server 2010 servers in each office.  You need to design Active Directory to meet the following Exchange Server 2010 requirements：.Users must be able to access their mailboxes if a single domain controller fails .Users must be able to send e-mail messages to the Internet if a WAN link fails  What should you include in the design？（）

单项选择题 You have an Active Directory forest. You plan to deploy an Exchange Server 2010 organization thatcontains the following servers：.Two Edge Transport servers.Two Hub Transport servers You need to recommend changes to the organization to ensure that e-mail messages can be sent to theInternet if a single transport server fails.  What should you recommend？（）

单项选择题 Your company has an Exchange 2010 organization that contains multiple Hub Transport servers. You have a line-of-business application that relays e-mail messages by using a Hub Transport servernamed Hub1.  The application only supports sending e-mail to a single SMTP server.  You need to ensure that the application can relay e-mail messages if Hub1 fails.  What should you do？（）