I do not know what ancient civilizations you covered in your class. So the only answer i can provide is for you to look at the Ancient History Encyclopedia under Indus Vally Civilization. It is an edu site that compares and contrasts the Indus Valley Civilization to other civilizations that existed close to their time. It also provides a lot of information on who discovered the civilization. Hope this helps, sorry I couldn’t offer more.
Answer:
the horizontal coordinate system
Explanation:
Poor workers and the middle class
