three month's和three months'的问题 再一次提问

three month's和three months'的问题 再一次提问 是three-month还是 three-months对 three months' holiday 可以表达成three-month's holiday吗?为什么在这还要" ' in three month 在三个月里 month 有s么?months? three months 的同义词 in three months提问用什么 for three months用什么提问 he meets friends /three times a month/对three times a month提问 for more than three months用什么提问 first three months About three months before three months and half 和three and a half months 有什么区别?