after purification是什么意思

用法例句

The relationship between R＆D expense and net profit was analysized in the paper． The study shows， according to the income tax law， the reasonable more R＆D expense than last year will make the firms get more after－tax net profit． than before

分析了企业的研究开发费用与其税后净利润的相互关系，得出了在符合税法的相关条件下，适当增加研究开发费用反而会增加企业净利润的结论。