The summer vacation.The summer holidays两个单词都是可数名词,为何一个变复数一个不变呢

the summer vacation怎么写 My plan for the Summer Vacation 英语作文 The summer vacation is coming The summer vacation was pretty good.kuai 求 The Summer Vacation将来时 They ____ the summer vacation.( look ) he often travels ___ the summer vacation in the summer vacation与during the summer vacation有什么区别 we went to the mountains d------the summer vacation the summer vacation is coming. I'll share the holidays we went (camp) in the mountains last summer vacation where were you in the summer vacation 的答句 Mary visited the Expo last summer vacation.改否定句 it is the first___of our summer vacation(暑假） We go sailing during the summer vacation.改疑问句 The Greens___(go) to Shanghai for a vacation this summer. this Sunday是什么时态after the summer vacation是什么时态 The most interesting day in my summer vacation英语短文