Read these excerpt. One is from the text and one
from another source. Based on these excerpts, it is
reasonable to say that
А
blood types A, B, AB, and O are believed to be the
most unique blood types.
B
anyone who is blood type O can donate blood for
patients who have any of 600 known antigens.
С
with hundreds of known antigens besides A and B, it is
important for blood banks to have many types of blood.
D
if you do not have an A, B, or O blood type, then you
cannot be a blood donor.