At nine o'clock in the evening, the study room of the library is very quiet. Everyone is immersed in the ocean of knowledge, perhaps preparing for the postgraduate entrance examination, perhaps preparing for the upcoming CET-4 and CET-6, perhaps really enjoying their favorite books, or perhaps reviewing for the final exam.
In the classroom at nine o'clock in the evening, the evening self-study has ended, but there are still many students who have not rushed back to the dormitory. Instead, I choose to stay in the classroom, discuss and study with each other, and continue to enjoy the fun of learning.
In the laboratory at nine o'clock in the evening, it was not because the class was not finished, but because someone was still doing experiments.