The answer is 50%.
From the 'National Affairs' website, they conducted a study where they found that less than 20% of couples who married in 1950 ended up divorced, about 50% of couples who married in 1970 did.
And in regards to the basic unit of society question; the answer would be family. Family is the basic unit of society as it forms community and is the nucleus of civilisation.
It depends on the type of animal, but if, for example, you're talking about one lower on the energy pyramid (like a chicken, for example) then this is because of the energy distribution. When an animal consumes something else, it absorbs about 10 percent of the energy of that creature.
So, lets say a plant has 1000 units of energy. Then a bug comes along, and eats the plant, absorbing 100 units (10 percent) of that energy. Then, a chicken eats the bug, absorbing only 10 units of that energy. Finally, a human eats the chicken, getting only 1 unit of the original energy.
The reason that something like a bug has to eat less than a human, is because it gets more energy directly from the plant.
Answer:
Sleep, Eat, read, take walks, play with my dogs, cook, jog/run, work out, ride bikes, swim.
Explanation: