1、必修四unit 2词性转换名词形容词副词动词动词ing动词过去式动词过去分词struggle奋斗，拼搏struggling奋斗的strugglestrugglingstruggledstruggledoutput输出，产量output输出outputtingoutput/outputtedoutput/outputtedhunger饥饿hungry饥饿的disturbance困扰，打扰disturbing令人不安的disturbed被烦扰的，心神不安的disturb打扰，烦扰disturbingdisturbeddisturbedcirculation流通，循环circulate流通，循环ci
2、rculatingcirculatedcirculatedbattle战争battle争斗battlingbattledbattledequipment装备equipped装备的，配备的equip装备，配备equippingequippedequippedexport/exportation出口exporter出口商export出口exportingexportedexportedconfusion困扰，混淆confused困惑的confusing令人困惑的confuse使困惑confusingconfusedconfusedregret遗憾regretted/regretful遗憾的regr
3、ettedly/regretfully遗憾地regret遗憾，后悔regrettingregrettedregrettednutrition营养nutritious有营养的discovery发现discover发现discoveringdiscovereddiscoveredfocus焦点focus使集中focusingfocusedfocusedreduction减少reduced减少的reduce减少reducingreducedreducedunderlined划线的underline划线，强调underliningunderlinedunderlinedsummary总结，摘要summarize总结，概括summarizingsummarizedsummarizedcomment评论comment评论commentingcommentedcommented
