Answer:
East Ferris running out of water because the amount of available freshwater decreases when people use more than the amount that flows into their area.
It gives you a sign that digestion is having a hard time taking place.
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
