n.改良者

Maybe a pragmatic idealist insists of being an ameliorator with great care, and harvests the permanent happiness from it; 我相信在自然狀態(tài)下，人都是善良的，尋求幸福快樂是人生而具有的動機。

Maybe a pragmatic idealist insists on being an ameliorator with great care, and harvests the permanent happiness from it; 務(wù)實的理想主義者，也許一直堅持做著一個小心翼翼的改良者，并從中獲得持久的樂趣。

phosphate-gesso used as a soil ameliorator, which is able to significantly increase output of agricultural production.While its influence on agro-environment is needed to pay attention. 磷石膏作為一種土壤改良劑有顯著的增產(chǎn)效果,但對農(nóng)業(yè)環(huán)境影響如何值得研究。

amelior amelioration 改善,改進

adj.改善的；改良的