单项选择题
Which of the following BEST describes a virtual machine？（）
A.Host B.VDI C.Hyper-V D.Guest
单项选择题 Whichofthefollowingserverclustersoffersincreasedavailability，performance，andscalability？（）
单项选择题 WhichofthefollowingBESTdescribesaNAS？（）
单项选择题 Whichofthefollowingreplicationmethodsprovidesadisasterrecoverysystemwithminimaldowntimetonormaloperations？（）
