a unified scheme还是an unified scheme?

a unified scheme还是an unified scheme? 统一的界面是an unified interface 还是a unified interface?为什么是a？这后面是u u是元音不是么？ Unified scheme scheme scheme scheme scheme 英语翻译怎么翻译好呢?a unified engine torque actuator 英语翻译The only way an airline in an overall capped scheme could make a profit would be to close up shop, 英语翻译segmentation scheme：Draw a segmentation scheme to depict visually the market for your product. 英语翻译法案、限令还是什么,原文如下Colorado and Montana are tipped by officials in the region to join the five-state western US initiative to develop a common greenhouse gas emissions cap and an emissions trading scheme.还有这个i a还是an uniform 用a还是an 要用a还是an? 是a还是an 求通信翻译这句话：A Unified Treatment of Optimum Pilot Overhead in Multipath Fading Channels 编程里的map In a binary phase-shift keying (BPSK) scheme each logical 0 in the sequence is mapped onto an actual value -1 and each logical 1 is mapped onto an actual value +1. 英语翻译An Interspeed 340 tin free antifouling scheme for a 36 month in-service period of 6,000 - 9,000 sea miles per monthAn Interspeed 340 tin free antifouling scheme for a 36 month in-service period of 6,000 - 9,000 sea miles per monthAn Inter unified怎么读 这the unified