What civilization built cities at harappa and mohenjo dark and built a sanitation system

Harappa was, in fact, such a rich discovery that the Indus Valley Civilization is also called the Harappan civilization. The first artifact uncovered in Harappa was a unique stone seal carved with a unicorn and an inscription.

I believe someone else has answered this question but correct me if I'm wrong, it was the Indus Valley Egypt Mespotamia China

a. the astrolabe could determine the correct latitudinal location of the ship

on this day in 1913, henry ford installs the first moving assembly line for the mass production of an entire automobile. his innovation reduced the time it took to build a car from more than 12 hours to two hours and 30 minutes.