是half hour还是half an hour?

是half hour还是half an hour? a half hour还是half an hour? half an hour 是单数还是复数 an hour and half还是an hour and a half half an hour or a half hour? half an hour later half an hour造句 Half an hour. half hour =half an hour half hour half an hour 的意思有和区别? They talked for half an hour.请问 for half an hour是talked的状语吗? one and a half hour看做单数还是复数?half an hour an hour nad a half 还是one hour nad a half 是a half hours还是a half hour?a half后面是单数还是复数啊? Lucy will finish writing an email in half an hour.(对in half an hour提问）是HOW LONG 还是WHAT TIME. I pasted the exam easily.还是I passed the exam easily.或者说两个都可以吗？还有是half an hour passed,还是half an hour past after half an hour.是什么意思 half an hour? 什么意思? Half an hour =什么?