This sentence expresses the praise and affirmation of teachers' dedication to teaching and setting a good example for students. The sentence "training wholeheartedly is a model of a good teacher" means: training and educating students wholeheartedly to become excellent models and role models. "Heart-to-heart" means heart-to-heart, and "education" means cultivating education. The "mentor" here refers to an excellent teacher, and the "role model" refers to an example or an example.