单项选择题 Your company has an Active Directory domain. The company has two domain controllers named DC1   and DC2. DC1 holds the schema master role.    DC1 fails. You log on to Active Directory by using the administrator account. You are not able to transfer  the schema master role.    You need to ensure that DC2 holds the schema master role.  What should you do（）

多项选择题 You are decommissioning one of the domain controllers in a child domain.   You need to transfer all domain operations master roles within the child domain to a newly installed  domain controller in the same child domain.   Which three domain operations master roles should you transfer（）

单项选择题 Your company has an Active Directory domain.    You log on to the domain controller. The Active Directory Schema snap-in is not available in the Microsoft  Management Console （MMC）.    You need to access the Active Directory Schema snap-in.   What should you do（）