Lin Fan looked at the blackboard, which had no more space to write on. He put down the chalk in his hand and said, "The Twin Prime Number Conjecture is a huge project that needs to be carefully studied and explored.
"Let's end it here for today."
Hu Tian nodded in agreement and said, "Can we exchange contact information? It'll make it easier for us to discuss at any time."
"Of course, we can," Lin Fan replied.
Then, the two of them took out their phones and added each other's WeChat and mobile numbers.
Ring!
It was at this time that the bell that marked the end of class rang.
Hu Tian slowly left the classroom.
All the students' eyes were fixed on the podium and on Lin Fan.
Their eyes were red.
One lesson! An entire lesson!
Hu Tian and Lin Fan stood together and discussed the problem for an entire lesson!
In the end, they even added each other's WeChat and mobile numbers.
