Dear MrCATIA,
Thank you for your your support, because I have heard on some forums that there is difference license relating to this surface modelling, the worst is WSD, the middle is GS1 and the best is GSD. Because most of my work is about surface modelling, so I care about this problem.
They suggest me to check the license information, but I just see my license is "student license", no more information. That is why I question.