如果非要选的话,我选1,但我认为不需要出现two weeks,可以说once for half a month
1 once every two weeks应该是对的every two weeks 应该就行了像every two days 是每两天一次every second/other day 是每隔一天/一隔一
第一个是正确的once every two weeks
once every two weeks
1正解(其实根据语感来讲,我觉得不需要加上every)