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