(55) by reason of 由于,因为
(56) by the way 顺便地;附带说说
(57) by/in virtue of 依靠……(的力量);由于
(58) by way of 通过……方法/形式;经过,经由
(59) for ever 永远;永久地
(60) for good 永久地;永远地
(61) for instance 例如,比如
(62) for the better 好转,向好的方向发展
(63) for the moment/present 暂时;目前
(64) for the sake of 为了,为了……的利益
(65) for the time being 暂时;眼下
(66) from time to time 有时;不时