改善用英语可以说为"improvement".

关于这个词的来源，它来自拉丁语"improbare"，意思是"to make better".

例句：

There has been a significant improvement in her health since she started taking those vitamins.

（自从她开始服用那些维生素后，她的健康状况显著改善。）

The company has implemented several new policies to improve customer satisfaction.

（公司实行了几项新政策，以提高客户满意度。）