Answer:
The words to complete the sentences are Metropolitan cities, nomadic hunting.
Step-by-step explanation:
The densely populated urban areas are referred to as metropolitan cities. Some of the densely populated urban areas are referred to as Greater metropolitan cities or mega pols, etc.
While now we live a settled life, our native groups in the ancient times have been practicing nomadic hunting, gathering and subsistence agriculture.
The integration due to the technological advancement is good, though this integration requires large amount of responsibility in usage and management of the natural resources.