improver
noun [ C ] uk/ɪmˈpruː.vər/ us/ɪmˈpruː.vɚ/
改进者；改进物
someone who makes changes to something in order to improve it
home improvers 进行家居修缮的人
UK进步者，提高水平者
someone who is becoming better at a skill
We run swimming classes for improvers. 我们为游泳水平提高者开设游泳课程。
UK改良剂
a substance that is added to something to improve its quality
Our bread does not contain preservatives, flour improvers, or other additives. 我们的面包不含防腐剂、面粉改良剂和其他添加剂。
soil improver 土壤改良剂