None 儿童 人民 白种人种族 A boy colors among papers on the floor as his dad works at his desk in the background
A diagram of the human skeleton, circa 1900. (Photo by Hulton Archive/Getty Images) 白色背景 解剖 人类的表示形式 Human Skeleton
A diagram of the human intestines. 'Figura de Situ Viscerum' From Magnus Hundt's 'Antropologium de Hominis Dignitate, Natura et Proprietatibus', Leipzig, 1501. (Photo by Hulton Archive/Getty Images) 人类肺癌 白色背景 解剖 Figura De Situ Viscerum
A diagram showing back and side views of the human skeleton, circa 1900. (Photo by Hulton Archive/Getty Images) 白色背景 解剖 人类的表示形式 Human Skeletons