n.改良者
Maybe a pragmatic idealist insists of being an ameliorator with great care, and harvests the permanent happiness from it; 我相信在自然状态下，人都是善良的，寻求幸福快乐是人生而具有的动机。
Maybe a pragmatic idealist insists on being an ameliorator with great care, and harvests the permanent happiness from it; 务实的理想主义者，也许一直坚持做着一个小心翼翼的改良者，并从中获得持久的乐趣。
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. 磷石膏作为一种土壤改良剂有显著的增产效果,但对农业环境影响如何值得研究。
amelior amelioration 改善,改进
adj.改善的；改良的
