短語詞組短語an average of years 平均2年an average of months 平均14個月an average of 1 平均值為an average of 6 years 平均年rise by an average of 遞增an average age of years 平均年齡32歲an average of 2 years 平均年an average of 4 years 平均年an average of 14 months 平均個月 返回 an average of