Have you ever experienced a miracle, in christmas time in particular?
No.
Do you think that some things they happen can't be explained?
I believe that are only things that can either be explained, or cannot yet be explained. There is nothing that is absolutely 100% impossible to explain either now or in the future - only time will tell if our scientific understanding develops enough for certain things to become explainable.
Do you believe in supernaturalism?
No.