The existence and maintenance of a relatively stable internal condition despite fluctuations in its external environment is known

Homeostasis

Explanation:

Homeostasis is the maintenance of a stable internal environment. The body does this by ensuring balance in salt-water, electrolyte, temperature levels.

Homeostasis requires the effects of hormones and nervous coordination to neutralize the external flunctuations such as temperature changes, osmotic shock etc

i would have a lunch. it's one big package of food, making it one food. : p

it's unlikely a majority of a large population would agree on issues

hope this : )