急急急!!吸血新世紀

Firstly, they are not zombie ,they are vampire.
1)It have no reason,but most of them in the movie are because of they are kill by someone or going to died and Carlisle want to save their life so they became vampire.
2)Edward said that he want to protect Bella 's soul and also is because of TURE LOVE.
3)human protect vampire may be is because of the afraid that vampire will kill them.

hope it cam help you

2014-04-15 21:46:52 補充：
*3)human protect vampire may be is because of they afraid that vampire will kill them.