This question is very debatale since this happened in acient Egypt. Try process of elimnation. They used all 4 of the options listed below. But the one that stands out the most is physics. In order for them to have figured out the early forms of glass, the Egyptians scholars had to have used studies of matter and motion to figure out the energy and force to find how to construct glass.
<span> By April 1975, a Communist group known as the Khmer Rouge, led by Pol Pot, seized control of </span>Cambodia<span>, renaming the country Democratic Kampuchea. ... The Khmer Rouge persecuted the educated — such as doctors, lawyers, and current or former military and police.</span>
