face to face面对面(的)地;对立地
face up to大胆面向
fall behind落在……后面,跟不上
fall in love爱上某人
fall out脱落;争吵,闹翻
far from远离,远非
feel like感到想要做
figure out计算出;估计
fill in/out填写
find out查明;找到;发现
first of all首先,开始时
for ever永远
for example例如
for good永久地
for instance例如
for the sake of为了……的利益
for the time being暂时,眼下
from time to time不时,有时