What happens when a dielectric material is placed between the two charged plates of the capacitor

Due to polarization of charges on either side the dielectric, it produces an electric field of its own which acts in a firection opposite to that of the field due to the source.

conduction, convection, radiation

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.