Answer:
They protect you against illness and disease. Think of white blood cells as your immunity cells. In a sense, they are always at war. They flow through your bloodstream to fight viruses, bacteria, and other foreign invaders that threaten your health.
The pH scale measures the concentration of how acidic or basic something is. The lower the number below 7, is acidic. Above 7 is basic. 7 is waters purest form.
If your asking where Most people in cities get there water.
Then the answer is by delivery through pipes.
D, they need to be able to absorb and keep water to prevent drying out