The earliest known precursor to football—or soccer, as it is known in some parts of the world—cuju is an ancient Chinese game that involves passing a ball through an opening into a net using only one’s feet. Originally part of the military’s fitness training regimen, the sport gained traction in the royal courts and among the upper classes in around 200 BCE. Cuju games were then standardized, and rules were laid out. With what were cuju balls initially filled? Discuss