A would be the best answer hope this helps
As distance between the two objects increases the force of gravity decreases. Hope that helps!
Natural selection is a theory developed by Charles Darwin. It is believed that animal species evolve by nature "selecting" the ones that are fit to live in specific environments. For example, if an animal lacks a trait that is needed for a certain environment, it is likely to die. The animals that have the needed traits are more likely to live and procreate, which will pass on the trait to its offspring. Hope this helped!
Since living organisms require energy and both survival and reproduction... the sun provides the energy for photosynthesis. Cells need sugar as a sources of energy. The cellular respiration is the synthesis of ATP using energy that is being released by the breakdown of sugar to carbon dioxide and water.
A tumor is a mass of abnormally growing cells.