单项选择题 Whichofthefollowingallowsmultipleapplicationstoshareasingleoperatingsystemresource？（）
单项选择题 HowcanaJFS2filesystembeaddedtoavolumegroupthathasinsufficientspacetohostalogLV？（）
单项选择题 Arecentlyinstalledpackageneedstoberolledbacktoapreviousversion.Whichofthefollowingcommandswillperformthetask？（）