For example, oxygen (o₂) diffuses from the air sacs into the capillaries of the lungs because there is a concentration of oxygen in the alveoli (air sacs) than the capillaries.

High. because the o² and co2 exchange gas in alveoli.. co2 in red blood cell bcos it comes from the cell

Three reasons of the deaths of native americans: new illnesses that their immune systems couldn't cope with. genocides so the settlers could have the good land.starvation from lack of rations and poor infertile land on resevations

The answer would be dogs.