单项选择题

案例分析题

The four blood types are【C1】______as A，B，AB，and O.Blood type A【C2】______red blood cells that have a substance A on their surface.This type of blood also contains an antibody directed【C3】______substance B，found on the red cells of persons with blood type【C4】______.Type B blood contains the【C5】______combination.Blood type AB contains【C6】______antibody，but red cells in this type of blood contain both A and B substances.In type O blood，neither substance is【C7】______on the red cells，but the individual is【C8】______of forming antibodies directed against red cells containing substance A or B.If blood type A is transfused【C9】______a person with B type blood，anti-A antibodies in the recipient will【C10】______the transfused A red cells.Because O type blood has【C11】______substance on its red cells，it can be given successfully【C12】______almost any person.Persons with blood type AB have no antibodies and can receive【C13】______of the four types of blood；thus blood types O and AB are called universal donors and universal recipients，【C14】______.
【C15】______hereditary blood-group systems have【C16】______been discovered.The hereditary blood constituent called Rh factor is of great【C17】______in blood transfusions because it creates reactions that can threaten the life of newborn【C18】______.More than twenty【C19】______blood types have been discovered.Their primary importance is in【C20】______cases involving proof of father-and-child relationship.

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