How to Breathe: the complete story

Ch. 1
For land mammals, such as me:

1. Suck air into your nose (if you have a cold, use mouth).
2. Pull air into your lungs.
3. Remove oxygen from air in lungs
4. Push air out.
5. Repeat.

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Ch. 2
For non-mammal water animals:

1. Open mouth.
2. Suck water into your mouth.
3. Shut operculum.
4. Close mouth.
5. Open operculum.
6. Let oxygen through gills into blood.
7. Repeat.

For marine mammals:

1. Go to the surface of the water.
2. Suck air into blow hole.
3. See steps 3-6 in Chapter 1.

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Ch. 3
For trees:

1. Open stomata in leaves.
2. Absorb carbon dioxide into leaves.
3. Push oxygen out stomata.
4. Repeat.

For air:

1. Do nothing because you're filled with oxygen.
2. Repeat.