You will discover 4 blood forms: A, B, AB, or O. Also, blood is both Rh-constructive or Rh-detrimental. So When you've got style A blood, It can be both A optimistic or possibly a damaging. Which type you are is important if you want a blood transfusion. And also https://www.youtube.com/watch?v=buIHtQY7fCU