unnel隧道UNabbr.(=United Nations) 联合国pron.<口>人，事物，家伙，东西uncontrolled settlement违章住区undisclosed association[经] 不公开的联合； 未公开的组织uncoordinated extension不协调伸展uncontrolled combustion无控制燃烧unprofitable aggression无益攻击Unconsolidated sihstone第四系uncoursed random rubble不分层乱石圬工uncompensated liability违约债务unconfined seepage flow无压渗流undisturbed frozen soil原状冻土