How to teach hard pen calligraphy when juniors and seniors are mixed together? And there is no way to unify the time.

Personally, hard-pen calligraphy teaching is different from ordinary textbook teaching, and its learning progress and ability to master skills have nothing to do with age. In other words, some junior students may have mastered the essence of hard-pen calligraphy, while some senior students have only learned one level of calligraphy because of their short contact time. So it should be no problem for senior three students to learn calligraphy together.