Umd
abbr. 便携数字智能产品（Ultra Mobile Devices）；PSP专用光盘（Universal Media Disc）
🗣️ 情景例句
OK.
好的。
What's the weather like today?
今天天气如何？
But here we come up against the most difficult of all obstacles to contact with people on other planets ----the astronomical distances which separate us.
然而，在和外星人联系中我们遇到的最大困难是分隔我们的天文距离。