UNCCD联合国防治荒漠化公约UNabbr.(=United Nations) 联合国pron.<口>人，事物，家伙，东西unconvicted detention未决羁押unempathic individual无同情心者undeliverable mail.无法发送的邮件undetermined constant未定常数undistributed deficit未弥补亏绌<赤字>uncontrollable factor不可控因素unpolarized continuum非偏振连续谱unlined paper/skin无横格的纸；无皱纹的皮肤uncoupling conditions解环条件unconformation degree不确定度