1.flexible a.易彎曲的，靈活的(elastic)

詞根記憶：flex(彎曲)+ible--易彎曲的，靈活的

例：Time management needs to be firexible so that employees can respond to unexpected problems.

2.flip v.輕彈(to flick)；按（開關）(to press a button or switch)；蹦跳a．無禮的 (rude)；冒失的；輕率的(flippant)

聯想記憶：f（看作fly飛）+1ip（嘴唇）--飛吻輕拋一無禮的

例：flip over翻頁

派生詞:flippant(a．輕率的；沒禮貌的)

3.flippant a．無禮的(impolite)：輕率的(rude; casually disrespectful)

例：lf your flippant attitude doesn't improve, you're going to be fired.

4.flock n.（鳥、獸等）—群(a group of animals, e.g. birds or sheep etc.)

聯想記憶：和block(v.妨礙)一起記

例：a flock of large birds一群大鳥

5.flourish v.繁榮(to thrive, to prosper)；活躍(to be in a period of highest produc-tivity, excellence, or influence)

詞根記憶：flour( =flor花)+ish--花一樣開放--繁榮

例：People are friendly, the environment is safe, and the arts are flourishing.//This bacterium can flouriish on the dried grain.

6.fluctuate v.(使）漲落,（使）變化(to swing)

詞根記憶：fluct(=flu流動)+uate--波動--變化

例：A minority shareholder buys and sells stocks as prices fluctuate over short periods of time.

7.fluctuation n.波動(swing)

詞根記憶：來自fluctuate(v.波動)

例：Such fluctuations in population are known as population cycles.

8.fluid n.流體(liquid)；a．流體的，流動的(able to flow freely, as gases and liquids do)

詞根記憶：flu(流動)+id--流體；流動的

例：These rats stay in burrows to avoid loss of fluid through panting or sweating.

派生詞:fluidounce(n.液量盎司)