Using the idea of "really visible time" introduced by Liu Ciyuan, this problem can be solved.

刘次沅率先引入“可见时间段”的概念，使这一问题的解决成为可能。

youdao

Using the idea of "really visible time" introduced by Liu Ciyuan, this problem can be solved.

刘次沅率先引入“可见时间段”的概念，使这一问题的解决成为可能。

youdao