hour前因该用介词a还是an

hour前因该用介词a还是an hour前用a还是用an onion前用介词a还是an right前的介词用a还是an? unifrom前用什么介词,是an 还是a? a hour 还是 an hour?hour 前面到底是用a 还是an? a hour 还是 an hour如题如题如题 a one -hour还是an one-hour a half hour还是half an hour? seventy mile an hour前跟什么介词 an hour and half还是an hour and a half exciting前面介词用a 还是an 英语中hour前为什么用an 冠词 an one-hour 还是a one-hour 是a one-hour ducumentary还是an one-hour documentary half an hour 的主谓一致问题half an hour 作主语时,谓语动词应该用单数还是复数?one hour and a half 呢? hour 前加的为甚么是an不是a mp3前用冠词a还是an