There is another form of vitamin a that coats the inside of the cells with a protective lining that sustains the skin of the cell as it heats up in the act of cell metabolism (digestion of sugar).

第二种维生素a用一层支持细胞表皮的保护层把细胞从里面包起来，因为在细胞代谢(消化糖类)中细胞表皮会变热。