Macromolecules:

which foods do you think will enter blood the quickest. why?

Macromolecules are large polymers, such as carbohydrates. Polymers are large chains of similar repeating subunits called monomers. The least complex type of carbohydrate are the monosaccharides (glucose, fructose, ribose). To answer your question, simple sugars (glucose) would enter the blood quickest. Hope this answer helps.