Every week为什么不用weeks

Every week为什么不用weeks every week还是every weeks?为什么不能是every weeks?到底是哪个. 英译中every four weeks every fourth week they go fishing_________A.each other week B.every other week C.each other weeks D.every other weeks选哪个?为什么?意思是? every second week every two weeks 有什么区别 We'll have four weeks' holiday.中为何不用week's或weeks,而用 weeks'? my sister came back home ______A: every two week B: every third weeks C:every two weeks D:each two weeks帮忙解析一下。。 不知道答案 Dose she have to wash clothes every week?请问为什么不用has? he goes to the cinema ().填every two weeks 还是every two week.哪一个对 为什么He bought one or two new CDs every week.动词不用buys?every 不是频度副词吗? Every year I have___holiday.A:a two-week B:two weeks C:two-week D:two week's we must rest from playing for a week or two weeks every year 翻译 I_violin lessons every two weeks,but i think i'll make it every week from next monthA.am having B,have had C.have D.have been having我认为前半句是一般现在时选C,可答案选D为什么? my mother has a lot of housework to do every week中为什么用to do,而不用do every word为什么不用every words 英语翻译every day for two weeks,every day for five months is fine .but don`t go faster than every day for one week Peter comes to see his grandpa every few weeks.中文?为什么用every? two weeks' time为什么要有“ ’”two weeks'time two week's time two weeks time有什么不一样?哪一个是对的?