In order to live.
Oxygen is the gas humans and animals need to breathe in.
Absolutely. It's what we breathe.
Humans breathe in oxygen and breathe out carbon dioxide. Trees "breathe" out oxygen.
Humans are dependent on oxygen, we need it to breathe and live.
Oxygen is what humans breathe in. We need it to be alive.
Oxygen we inhale oxygen and exhale carbon dioxide
Squirrels need oxygen, just as humans do, so they breathe in air much the same way as humans do. Squirrel blood cells need oxygen to operate their muscels, bones, and anything else in their body, much the same need for oxygen in humans.
to live and
Photosynthesis provides the oxygen humans need to breathe. Plankton are the biggest producers of oxygen and contribute greatly to the survival of humans.
Humans breath to provide oxygen to the cells throughout the human body. Cells need food and oxygen and in return produces heat, CO2, and energy. Therefore, humans need to breathe in order to "feed" their cells, as well as to get energy to power their body.
That means that oxygen is necessary for life to survive. Humans need oxygen to breathe and use for cellular respiration.
They breathe in oxygen like humans.