短語詞組短語accident cumulative frequency method 累計頻率accident injury frequency 意外事故傷害頻率Accident t Frequency 事故頻率accident accumulation frequency 事故累計頻率fatal accident frequency 死亡事故頻率accident frequency method 事故頻數(shù)法high accident frequency location 經(jīng)濟(jì)發(fā)生事故地點accident frequency rate 意外傷亡事故頻率;非人為;意外事故發(fā)生率;意外事故頻率 返回 accident frequency