As time goes on, members of a population with favorable traits continue to breed while those without these traits eventually die off. For instance, if all of the food in an area was high up in the trees, only members of the species with long necks are able to eat and continue to live and reproduce. Those with shorter necks will not be able to eat and will eventually die off. Over time, the species will evolve to have long necks.
Hope this helps!
B is true, however that is not a way in which conserving and recycling paper helps manage energy sources...
B. An apple about to fall from a tree branch
This is because potential energy is the energy before its actuall motion, or before kinetic energy (energy in motion). And the apple ABOUT TO FALL mentions a gravitational example.
B, is older
Because if you look on the scale b is deeper