是at the summer 还是 in the summer 还是on the summer

是at the summer 还是 in the summer 还是on the summer 是in summer 还是in the summer at summer 还是IN SUMMER the summer 前加on还是in还是at 在暑假是on summer还是in summer还是at summer 是in summer还是on summer in a summer night还是at a summer night 在暑假 翻译在暑假是In summer holiday ,还是in the summer holiday 四季的说法是什么?in the summer 还是 in summer? 想询问‘‘北京天气如何’’,应说 what's the weather like at summer in beijing 还是 what's the下面 weather like in summer in beijing /////? ( ) the summer holiday 填in还是on 是in summer vacation还是in the summer vacation啊?我班同学因为这个吵了一节课. 是at night还是in the night ( )many people at the beach in the summer? 请问是in summer vacation还是on summer vacation? 在夏天是用in summer 还是on summer The average temperature in summer in Qingdao is( )30是above还是below In summer it is hot in the day and cool at night.summer前面有逗号