A. the law of the unity of knowledge imparting and ideological and moral education

B. the law of combining indirect experience with direct experience

C. the law of the unity of teachers' leading role and students' main role

D. the law of the unity of mastering knowledge and developing intelligence

Basic laws of teaching process: ① Indirect law-the combination of questioning experience and direct experience; (2) the law of development-the unity of mastering knowledge and developing intelligence; (3) Education law-the unity of imparting knowledge and ideological and moral education; ④ Bilateral law-the leading role of teachers and the main role of students are unified.

Answer A analyzes the law of the unity of knowledge imparting and ideological and moral education, also known as "the law of teaching education", which means that the teaching process is not only the process of imparting and learning systematic cultural and scientific knowledge, but also the process of students receiving ideological and moral education on the basis of mastering knowledge, and the two are closely related.

Herbart first put forward "teaching is education", that is, teaching should not only impart knowledge, but also educate students in ideology and morality. Teaching is always educating people, and teaching must be combined with educating people, which is an inevitable link in the teaching process and the basic law that teaching must follow. So the answer is a.