How does the upper respiratory system support good health?

by moistening, heating, and purifying air as it proceeds down the airways

by removing dangerous carbon dioxide gases built up in the tissues

by providing oxygen to the cells

by preventing people from swallowing air

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)

Think it's rice because in many countries rice is the main food so it can be traditionally served all at once.