1. Lecture mode: Ding Fan's lectures are humorous and can accurately hit the key points of the exam, while Zheng Guo's lectures are boring and the teaching atmosphere is dull.

2. Teaching methods: Teacher Ding Fan is good at breaking the traditional memory teaching through scientific methods and using various ways to help students improve their grades, which is very popular among students. Zheng Guo used traditional teaching methods, and the communication was not smooth, so Ding Fan spoke very well.