Vitamins A, D, E, and K are fat-soluble. B vitamins and vitamin C, on the other hand, are water-soluble. Vitamin A. Vitamin A is found in many yellow-colored fruits and vegetables. Good sources include: sweet potatoes; winter squash; carrots; dark leafy-green vegetables; fatty animal tissue, such as liver or fish
A negative externality (also called external cost or external diseconomy) is an economic activity that imposes a negative effect on an unrelated third party. It can arise either during the production or the consumption of a good or service.
A network effect is the positive effect described in economics and business that an additional user of a good or service has on the value of that product to others. When a network effect is present, the value of a product or service increases according to the number of others using it. The classic example is the telephone, where a greater number of users increases the value to each. A positive externality is created when a telephone is purchased without its owner intending to create value for ot