A large pool of unskilled laborers developed.
Explanation:
They were mostly found on the south side but was sometimes found on East side
The correct options are B AND D.
Agriculture was the major means of survival for men during the early days. Fluctuations in the rainfall during the course of a year may adversely affect the crops grown. If this persists for a long time it will leads to food shortage and famine.
Earthquake and eruption volcanoes are shift in the physical environment which can easily destroy any community.
B) Work for other. Sometimes people do it their selves but most of the time people work for others for quick money