英语 一周两次 和两周一次 怎么表达 every two weeks once in a while 怎么翻译啊

twice a week,once two weeks

every two weeks once in a while
每两个星期一下

一周两次 twice one week
和两周一次 one time every two weeks

twice a week一周俩次
once in two weeks 俩周一次

every two weeks 每两周一次 once in a while 偶尔
Twice a week once every other week

twice a week
once two week

2 times per week
once per 2 weeks
每隔两周偶尔。。。