If we think of the human body as a system, how does eating food relate to feeling hungry and to the digestive system? A. Eating is the purpose of the human body system. B. Eating is only an output of feeling hungry. C. Eating is only an input for the digestive system. D. Eating is a feedback between hunger and digestion.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

Assuming you're referring to significant figures, none of these answer choices are shown to be zero as significant digits. did you, by chance, forget to add something?