C87 Listening in
"Tuk, tuk!" Ning Yin, who was sitting in front of the desk reading, suddenly heard a knock on the door.
She put down the book in her hand and got up to open the door.
At the door, Lu Anxin crossed her arms in front of her chest and looked at her with a smile that was not a smile.
"Is something the matter?"
"Can I come in?"
Ning Yin looked at her and thought for a moment