Cholangiocarcinoma is a rare cancer found in the tissue of the bile ducts, occurring in approximately two out of 100,000 people. Men and women are equally affected and most cases occur in people over age 65. The bile duct is a small tube that connects the liver and gallbladder to the small intestine. The ducts carry bile -- the liquid that helps break down fat in food during digestion â out of the liver. Tumors can develop anywhere on the bile ducts and are typically slow growing.
Soil formation is a long slow process. It's estimated that an inch of soil takes 500 to 1000 years to form. Soil is constantly being formed. It is also constantly being eroded.
Soil erosion occurs when soil is removed through the action of wind and water at a greater rate than it is formed. The soil covering the surface of the earth has taken millions of years to form and we must learn to respect it. Soil is formed at a rate of only 1 cm every 100 to 400 years and it takes 3 000 to 12 000 years to build enough soil to form productive land. This means that soil is a nonrenewable resource and once destroyed it is gone forever.