年数合计法折旧 sum-of-the-years digits depreciation: 总和年数折旧法sum-of-years-digits depreciation method: 年数总和折旧法sum of years digits method: 逐年指数法sum-of-the-years-digits: 年限积数法sum of the years digits method (sy: 年数总和法下载手机词典可随时随地查词查翻译