(1) The first floor of the "Balanced Diet Pagoda" is cereals, which mainly provide sugars such as starch. Sugar is the main energy-supplying substance for human body, and most of the energy needed by human body for various life activities comes from sugar, so to meet the supply of sugar, a large proportion of cereals should be eaten in the diet; After entering the digestive tract of human body, sugar is preliminarily digested in the mouth, thoroughly digested into glucose in the small intestine, and absorbed into the blood circulation in the small intestine at the same time. < P > (2) protein is an indispensable substance in human tissues, and it is also the main component of various enzymes, antibodies and certain hormones. Children and adolescents are at the critical period of growth and development, so they should eat more foods rich in protein, such as the foods in the third and fourth layers in the table, to ensure growth and development.

So the answers are: (1) cereal; Sugar; Small intestine;

(2) There are more protein.