Underline details in the text about the ancient cities of mohenjo daro and harappa in ancient india how are archaeologists able to determine these details about cities that no longer exist ?

An archaeologist was able to determine the sites by the bricks similar but was old found in the area where they lay railroads.

Explanation:

While railroads were constructed in Pakistan the engineers were searching for ballast which is used for railroad construction to drain water from the railways.Archaeologists later discovered the settlements along the Indus river, thousands of clay pellets with writings older than Sumerian, combs, pottery, seals, urban, plans with grid pattern during the excavation process.Both Harappa and Mohenjo Daro is a part of Indus Valley Civilization. The period of the excavated materials and artifacts is determined by the process name called Radio-Carbon Dating in which the age of the carbon can be accessed.