The digestive canal represents a tube passing through the entire organism and communicating with the external world, i.e. as it were the external surface of the body, but turned inwards and thus hidden in the organism. ↗
Edible substances evoke the secretion of thick, concentrated saliva. Why? The answer, obviously, is that this enables the mass of food to pass smoothly through the tube leading from the mouth into the stomach. ↗
There are nearly 200 countries and a population of over 6 billion in today's world. International affairs should be addressed by all countries through consultations rather than monopolised by a few powers. ↗