To master advanced mathematics, students must keep at their practice consistently.

keep 的意思是"保持、继续"，表示维持某种状态或行为。 at 在这里与 keep 搭配使用，keep at 是一个短语动词，表示"坚持做某事"。 keep at their practice 意思是"坚持他们的练习"，强调持续不断地进行练习。