a change in quality

• 质变

a change in quality的用法和样例：

例句

1. Quantitative change is the necessary preparation for qualitative change.
   量变是质变的必要准备。
2. For one can fairly say that ties between the two sides have undergone a sea change in recent years and Taiwan's economic future is now bound closely to the Mainland.
   可以说在过去几年来，两岸的关系已经发生了质变，台湾的经济前途，已经和大陆密切相关。