The answer is air.................. lol it said I have to add 20 characters or more so
Sorry but I do not understand your question
Answer:
Red blood cells (erythrocytes)
Red blood cells carry oxygen from your lungs to your tissues. They also bring carbon dioxide back to your lungs. Red blood cells make up almost half of your blood. The lifespan of a red blood cell is around 120 days
Explanation:
Answer:
The answer is natural selection.
Explanation:
Natural selection will make an organism to survive and reproduce because, it will be better suited to the environment.
This is the reason why natural selection is considered as a key mechanism of the evolution.