Answer:
Tomorrow
Explanation:
The one-word answer to this simple riddle is 'Tomorrow'. Tomorrow never comes, but people always push back their plans and say that they will "do it tomorrow". So tomorrow is always coming but it never actually arrives.
Hey! You can improve and maintain good health of an elementary school age child by making sure they get regular enjoyable exercise, have proper healthy balanced meals, and that they are learning and interacting with others their own age well. I wish you all good health and positive energy! :) - Aspen