Answer:
All of these are natural resources.
Explanation:
Because they are not manufactured.
A. external
These types of signals are observed when there is a cut on the body. The epidermal cells lose contact with one another and divide faster until they are in contact once again. After they come into contact, division slows down again.
The four postulates of the natural selection include.
1. individuals possessing particular traits are have higher likelihood of surviving and reproducing.
2. different individuals in a population have different traits
3.reproductive and survival rate vary with individuals in a given population.
4. some trait differences are inheritable.
The Ecosystem will be out of balance.