一级理论和二级理论的区别

The three words were very soft, and if it wasn't Ning Cheng's level of cultivation, he wouldn't be able to hear them clearly. Ning Cheng suddenly felt a little bored. He and Tian Muwan had been together for more than a day or two. He knew Tian Muwan very well, at least he had never heard Tian Muwan say these three words....