First, get an education so as to pose an intelligent and coherent question.
Secondly, seeing as the author, who has control of who lives and who dies in her literary world, has her own website, this question is better asked there (Jo Rowling's website).
It has also been said because it was unexpected, as Fred always seemed like the stronger twin, more predicted to lose George. While it was really sad, she made a good suprise. Also, George did lose an ear.