Nutrients absorbed by human body: sugar, fat and protein.

The main source of energy is sugar.

Nutrition: sugar, crude fiber, vitamins, fat, protein, water and inorganic salts. * * * Seven kinds

One gram of sugar can release 6.8 kilojoules of heat whether it is completely burned in vivo or completely oxidized in vitro.

Transportation of human body: blood

Blood: plasma (yellowish translucent water)

Blood cells (red blood cells, white blood cells, platelets)

Blood cells: Red blood cells: disc-shaped seedless, and hemoglobin "Fe (iron)" transports oxygen and carbon dioxide.

White blood cells: defensive, with the least number, nucleated and large volume.

Platelets: the smallest, nucleated, accelerating coagulation.