.in fear of (=afraid for the safety of)担心
.feed (sb.) on sth. 靠吃……，用……喂养
.be fed up with (=be unhappy, tired about sth. dull)厌烦，腻了
.feel like (=have a desire for)想要
.fill in填写
.fill out (=fill in)填写
.set the world on fire = set the flames on fire (=do sth. remarkable)有突出成就
.play with fire (=take great risks)干冒险事
.set sth. on fire (=set fire to sth.)使……着火，放火
.at first sight (=when first seen)乍一看，一见
.for the first time第一次(作状语)
.in the first place首先，第一
.fit into刚好放入
