About three things I was absolutely positve. First, Edward was a vampire.  Second, there was a part of him, and I didn't know how dominant that part might be that thirsted for my blood. And third, I was unconditionally and irrevocably in love with him.

1、sb. be absolutely positive某人完全可以肯定

2、vampire 吸血鬼

3、revoke v.撤销，取消

revocable adj.可撤销的，可挽回的

irrevocable adj.不可撤销的，不可挽回的

irrevocably adv.不可挽回地，彻底地