Undelivered Orders未发货订单 Unusual Occurrence异乎寻常的事 University Outreach大学外展 Ultima Online“网络创世纪” University of Oregon奥勒冈大学 University of Oklahoma奥克拉荷马大学 University of Ottawa渥太华大学 ureteric orifice输尿管口 Urban Outfitters城市Outfitters Unit Operator单位算子 University of Oxford牛津大学 Unexploded Ordnance未爆炸武器 Undercover Officer特务; 卧底 Official Envelope (Scott Catalogue prefix; philately)官方的回邮信封(斯科特目录前缀、集邮) Underoath (band)Underoath(带)