Use your vocabulary words to complete the sentences below.

More of the world's population is now concentrated in heavily populated urban areas known as a ____ . This is quite a contrast from the past when ____ or native groups were either farmers or ____ — hunters and gatherers who moved between places in search of food. Advanced technology has led to _____, the integration of world economics and cultures, in the world's more developed countries. This integration requires increased ______ , the responsible use and management of natural resources.