倍投在数学中简介：Cai Gen Tan is her favorite book. On her sixteenth birthday, her parents gave her a copy of Cai Gen Tan, a sealed ancient book, as a gift. Cheng Keshu liked the principles of life in it.
Cai Gen Tan is her favorite book. On her sixteenth birthday, her parents gave her a copy of Cai Gen Tan, a sealed ancient book, as a gift. Cheng Keshu liked the principles of life in it.
