1) Urea moves out of the liver cells into the blood plasma by diffusion. Describe how this happens.
2) how is it possible for oxygen to move from the alveolus into the capillary and why is this important?
3) how is it possible for carbon dioxide to move from the capillary into the alveolus and why is this important

you don't have to answer all at once but please answer asap :)

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

a lot of people sadly don't know the best way to learn is cheating off of your friends or this amazing thing called google

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers