Where the cancer starts is called the primary tumour. Some types of cancer, called leukaemia, start from blood cells. They don't form solid tumours. Instead, the cancer cells build up in the blood and sometimes the bone marrow. For a cancer to start, certain changes take place within the genes of a cell or a group of cells.
pommel horse. n. 1. A piece of gymnastic equipment that consists of a padded, loaf-shaped object with two pommels on top and stands horizontal to the floor, usually on adjustable legs. 2. An athletic event in which the pommel horse is used.
A green horse (or rider, for that matter) is a horse that has little or no training. Usually a horse is referred to as green after it's saddle broke, otherwise it's considered unbroke, halter broke, etc. When it comes to showing, a green horse is often a horse that has had less than 1 to 2 years of showing experience. Other times it's a horse with less than 2 years of under saddle training.