a half hour还是a haif hours

a half hour还是a haif hours a half hour还是half an hour? an hour and half还是an hour and a half one and a half hours 还是hour half an hour or a half hour? half a hour a half hour对吗 是a half hours还是a half hour?a half后面是单数还是复数啊? an hour nad a half 还是one hour nad a half one and a half hour看做单数还是复数?half an hour a half hour one hour对不对? one hour and a half加’s 还是s’ one boy is a boy,two boys haif boy,three boys are not boy.haif打错了，应该是half The journey takes_____.A.half an hour B.an hour half C.a half hour D.half a hour half an hour 和a half hour有什么区别? half an hour和a half hour一样吗? half an hour和a half hour一样吗? 是one and a half hours还是one and a half hour