Complex sentence: AD 900 to AD 1150--the the Ancestral Puebloans, lived in dwellings made of stone and mortar and enjoyed communal activities in kivas--a congregational space mainly used for ceremonial purposes, engaged in agriculture--planting corn, squash and beans.
Split into simpler sentences: AD 900 to AD 1150--the Ancestral Puebloans, lived in dwellings made of stone and mortar and enjoyed communal activities in kivas--a congregational space mainly used for ceremonial purposes. They engaged in agriculture--planting corn, squash and beans.