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.
Subsistence agriculture is a labor-intensive method of cultivating food crops, which is sufficient for the farmer and his family. The production is done on a small scale which is adequate to feed a small population. Self-sufficiency is primarily focused in subsistence farming, due to which surplus food is reduced.ubsistence agriculture is a labor-intensive method of cultivating food crops, which is sufficient for the farmer and his family. The production is done on a small scale which is adequate to feed a small population. Self-sufficiency is primarily focused in subsistence farming, due to which surplus food is reduced.