You Want A Permission Slip? Let Me Test You

There were two physics lessons during the three days of the mathematical modeling competition.

Lu Zhou felt like it was not a good impression to miss the first class and so, he decided to personally hand in the permission slip as he did not want to bother the class leader.

From the class information given by the Academic Affairs Office, the physics teacher was called Li Rongen and he was an old professor with high qualifications. When Lu Zhou found his phone number, he gave him a call to confirm that he was in his office before he headed over.

Lu Zhou knocked on the door before he walked in. He handed the permission slip on the desk and explained his reasons.

"Permission to miss classes?" said Professor Li. He took off his glasses and looked at the slip as he said, "Your name is Lu Zhou, right?"

"Yes," said Lu Zhou as he nodded.