291.on faith毫无怀疑地，依赖地
292.faithful to (=loyal to)对……忠诚
293.fall into the habit (of)养成……习惯
294.fall short of (=fail to reach a desired result， standard， etc.)没达到，低于
295.familiar with熟悉，了解
296.have a fancy for (=like sth. without the help of reason)(没有道理地)喜欢，想要
297.take a fancy to (=become fond of)喜欢
298.by far远，非常(与比较级或最高级连用)
299.far from远远不是
300.far from非但不……(而且)
301.in favour of赞成
302.be in favour with受宠，受偏爱; out of favour with失宠，不受宠
303.in fashion (=stylish，most modern) 时兴，流行
304.after the fashion (of)依照……
305.find fault with (=complain about;criticize)找毛病，对……吹毛求疵
306.at fault (=in the wrong， blamable)有错
307.in one‘s favour (=to one’s advantage)对……有利
308.(be) favourable to (=advantageous)有利的
309.fear for (=be afraid for the safety of sb. or sth.)为……担心
310.for fear of (=in case of; because of anxiety about)以防，由于怕
311.in fear of (=afraid for the safety of)担心
312.feed (sb.) on sth. 靠吃……，用……喂养
313.be fed up with (=be unhappy， tired about sth. dull)厌烦，腻了
314.feel like (=have a desire for)想要
315.fill in填写
316.fill out (=fill in)填写
317.set the world on fire = set the flames on fire (=do sth. remarkable)有突出成就
318.play with fire (=take great risks)干冒险事
319.set sth. on fire (=set fire to sth.)使……着火，放火
320.at first sight (=when first seen)乍一看，一见