Osteoarthritis (OA) . OA is the wear-and-tear arthritis that usually occurs with aging or after injury. With OA, there's a wearing down of the cartilage that cushions the ends of the bones. OA causes joint swelling in those joints that bear weight over a lifetime, such as knees, hips, feet, and spine.
During the Zhou dynasty, the Chinese developed irrigation and flood- control systems. As a result, farmers could grow more crops than ever before. Because more food could support more people, the population increased. During the late Zhou dynasty, China's population had expanded to about 50 million people. Zhou people also learned to use iron, which was cheaper and stronger than bronze. Iron weapons, the catapult and China's first cavalry (military on horseback) were some of the Zhou achievements that helped strengthen the army.
Home > Timelines > Zhou Dynasty Timeline. Zhou Dynasty Timeline. Timeline Description: The Zhou dynasty (c. 1046 - 221 BCE) lasted longer than any other dynasty in Chinese history. After overthrowing the Shang dynasty, the Zhou established a number of key traditions, including the importance of family and social order.