C24 It Had Become Popular on the Internet

"Everybody turn the textbook to page 85. Today we will review..." The class teacher, Xue Ningyu, who was wearing a black dress, was lecturing on the podium when she was interrupted by a knock on the door.

"Please come in."

The door of the classroom was gently pushed open. It was Meng Ran, who was carrying his schoolbag.

"Sorry, teacher Xue. I overslept