11前加a还是an

11前加a还是an orange前加an还是加a MP4前加a还是an不定冠词 MP4前加an,a还是the exciting前加a还是an 单词 uncle前加a还是an eraser前加a还是an? black eraser前加an 还是a Asian前加an还是a American前加a还是an? information前加a还是an banana前加a还是an 英语名词 加auseful前加a还是an 如何快速判断名词前加an 还是加a office前加an还是a?急求! S前加an还是a?越详细越好, 请问 high school student前加a还是an 元音音素aa前加a还是an