Sentence:  Dr. Wilson C. Grant , of the Veterans ' Administration Hospital , Coral Gables , Florida , and the University of Miami School of Medicine , set out to discover if avocados , because of their high content of unsaturated fatty acids , would reduce the cholesterol of the <WSD>blood</WSD> in selected patients . 
Meaning of the word marked with <WSD> tags:  the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets