Answer:
Spread
Explanation:
People use envelopes very often. The germs people carry are put into the envelope and then it's sent out to many others.
Over time, those who cannot live through the temperature differences/have undesirable qualities will die off. Overtime, those with desirable qualities are left and they will continue the population.
Answer:
The damage to ozone layer is done by halogens such as Chlorine and Bromine.
Answer:
c is just wrong because that is not how evolution works evolution is a small change in the DNA that takes a long time through many many generations not just as you or an organism get older and smarter you are not evolving