five score years ago的意思怎么是一百年前

before以过去某时为起点的......之前

ago以现在为起点的......之前

hetoldmethathehadfinishedhisuniversityfiveyearsbefore.(现在算起，毕业六年了)

hetellsmethathehasbeeninthefactoryfiveyearsago(入厂五年了)

供参考。