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.
The expression network effect is applied most commonly to positive network externalities as in the case of the telephone. Negative network externalities can also occur, where more users make a product less valuable, but are more commonly referred to as congestion (as in traffic congestion or network congestion).hen a network effect is present, the value of a product or service is dependent on the number of others using it. The classic example is the telephone.