unus一UNabbr.(=United Nations) 联合国pron.<口>人，事物，家伙，东西unresolved source不可分辨源unlearning motive非学得动机unfeathering pump回桨泵uncollected poems佚作unpositioned flap不复位瓣unblocking signal疏通信号uncinate epilepsy[医] 钩状回性癫痫unbias estimation无偏估计unusable undercut无用倒凹undulating fields起伏的田野