一级理论和二级理论的区别

After Ning Cheng finished speaking, Yu Qing looked at Ning Cheng with a shocked face. It was obvious that what Ning Cheng said was beyond her understanding. It's not that she doesn't want to believe it, it's that she simply has no way of believing it. At first she believed it, but the more Ning Cheng talked about it, the more she felt there was something wrong....