undwadj.水下的
UNabbr.(=United Nations) 联合国pron.<口>人,事物,家伙,东西
undathem facies浅海岩相
unfinned rocket无尾翼火箭
unbalanced area无界区
undrawn balance未提取的余额
unbroken furrow未碎垡片
unresolved peak未分辨峰
unbalanced mass不均衡质量
unwrapping tool解缠工具
unbroken rubber未塑炼生胶
unmanned launch无人驾驶飞行器的发射