Which view should a user query to display the columns associated with the constraints on a table owned by the user? （） [" USER_CONSTRAINTS"," USER_OBJECTS"," ALL_CONSTRAINTS"," USER_CONS_COLUMNS"," USER_COLUMNS"]
域名的概念及其法律特征
IBM SONAS provides extreme scale out capability, a globally clustered NAS file system built upon（）. ["NFS","GPFS","CIFS","NTFS"]
教育的直观手段有（）、（）、（）三种。
纳税人通过合法的手段以纳税最优化为目的，在纳税决策中所做的决策称为（）。 ["税收","避税","节稅","逃税"]
锅炉的热效率是指（）。
