短语词组用作形容词 (adj.)～+名词keen edge 锋利的刀刃keen interest 强烈的兴趣～+动词不定式keen to pass the examination 渴望通过考试keen to visit that city 很想去参观那个城市～+介词keen about going to the picnic 希望去野餐keen about 〔on〕 music 爱好音乐keen of hearing 听力敏锐短语 返回 keened