Answer: Human survival on Mars would require living in artificial Mars habitats with complex life-support systems. One key aspect of this would be water processing systems. Being made mainly of water, a human being would die in a matter of days without it.
Explanation: have a good day
The answer is D, white blood cells.
The main function of white blood cells is to defense the body from bacteria or other pathogens. There's 2 main kinds of white blood cells, lymphocytes and phagocytes. Lymphocytes mainly produce antibodies that can kill bacteria or any pathogens, and phagocytes can ingest the pathogens directly.
Therefore, since the white blood cells can protect our body, they're part of our immune system.
They are the first species that could live on dry ground.
So carbon dioxide can diffuse from the leaf
