in holiday 泛指放假，但说话人说话的时候并不在放假。如，i'd like to stay with my families in holiday.in the holiday  指特定的假期，根据上文的延续。如，Christmas is a spcial holiday in western countries. In the holiday, people usually stay with their families.on holiday 处于放假的状态如，i'm on holiday now.类似有on duty 上班中 另外补充一下，如果你前面曾经提起过某个节日，而现在针对这个节日说on，就要用on the holiday,特指在这个节日。否则，用on holiday. 

是on holiday 还是at holiday 或in holiday We have the T-shirt__red __only $20. A.on;for B.in ,for C.at ,on D.in,on {why?} in the bus 和 on the bus 的区别 in the ground 和on the ground的区别 on the street和in the street的区别 in the river 和 on the river 有什么区别? in the street 和 on the street 有什么区别？ in the tree和on the tree 区别~~~在线等!!! on the tree和 in the tree有什么区别 翻译:"the hat shouldn't be on the tv.we should put it in the wardrobe. In front of the person you love ,you can't say everything on you mind. One of the Most Interesting Activities in My Summer Holiday The holiday shouldn't cost very much. on the river? in the river? In the hallways 还是 on the hallways in the hallways 还是 on the hallways in the lift OR on the lift ?? 在树上有on the tree 和in the tree,怎么区分? in the next page和on the next page有什么区别？ in the street 和on the street 的用法及区别 "on the tree"和"in the tree"有什么区别？ on holiday 的意思 zoom in on the subject怎么翻译? on keeping pets in the dormitory