Both types of IUDs work primarily by preventing sperm from fertilizing an egg. The copper IUD releases copper into the uterus, which works as a spermicide. The others release a form of the hormone progestin into the uterus. The progestin thickens the cervical mucus so that sperm can't reach the egg.
Commercial agriculture. Commercial agriculture is a large-scale production of crops for sale, intended for widespread distribution to wholesalers or retail outlets. In commercial farming crops such as wheat, maize, tea, coffee, sugarcane, cashew, rubber, banana, cotton are harvested and sold in the world markets.
A market economy is an economic system in which individuals own most of the resources - land, labor, and capital - and control their use through voluntary decisions made in the marketplace. It is a system in which the government plays a small role. In this type of economy, two forces - self-interest and competition - play a very important role. The role of self interest and competition was described by economist Adam Smith over 200 years ago and still serves as foundational to our understanding of how market economies function.