summer holiday与summer holidays的用法及区别为什么有些加而又有些不加s呢?

summer holiday summer holiday Summer holiday in summer holiday与this summer holiday的区别或者用法,为什么有的时候不用加介词? for the summer holiday 与 in the summer holiday 的区别是什么 in summer holiday or on summer holiday My Summer Holiday plan my summer holiday 英语小报summer holiday enjoy his summer holiday Bad weather_my summer holiday 英语日记 summer holiday for the summer holiday 与 in the summer holiday 的区别是什么这俩句英语的区别是什么 请将下面的句子用另一种方式表达,1 What would you like to do in the summer holidays?2 What about going abroad for a holiday?3 Why not go to Beijing by plane?4 Excuse me,how can I get to the Tone Hotel?5 Going skiing in Australia in summe 是have summer holiday还是have a summer holiday summer holiday》80词就行了 英语作文：last summer holiday 英语作文A Summer Holiday