When a rat enters a Skinner box, it has to learn to press a lever to get food. At the very beginning of this process, it is rewarded with food when it is in the vicinity of the lever. Then it is rewarded when it touches the lever, and so on. This technique of rewarding successive approximations of a desired behavior is called

~kinetic ~potential

explanation:

kinetic and potential energies would be types of mechanical energies.

answer; proximity;

which sentences ? that question is incomplete

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.