Black tea, such as Liubao tea and Pu 'er tea. Because black tea is completely fermented tea, the higher the age, the more mellow the taste. When black tea enters the stomach, it will form a protective film attached to the surface of the stomach, which plays a protective role. Black tea can regulate the concentration of cholesterol and fat in blood and prevent hyperlipidemia and arteriosclerosis. In addition, black tea has collection value.