Before he reached Chen Chen's room, Chu Ao-tian heard Chen's happy laughter.

Instead of pushing the door in, he stopped in front of the door.

"... What's this, Mommy? The soft waxy and lively voice of children is Chen Chen.

"Ah, this, Mummy wants to read a book... Find it. It's called Bian Shi. The gentle and agile female voice is Waner.

"Why isn't it called blackstone? It's black." Chen Chen asks Mommy with a crooked head.

"Mommy doesn't know." Li Wanyang shook his head.

"What about this, Mommy," Chen Chen picked up another red stone. "Is this called garnet?"

"This is Shoushan Stone." Li Wanyang is still shaking his...