During which era did people move to cities and create instrumental pieces of technology?

Mammals first appeared during the Mesozoic era.Hope I helped, good luck!'

answer; they use longitude and latitude and   global grid system; good luck

all fossil fuels are nonrenewable, so think coal, gasoline, things that we will eventually run out of. all fossil fuels are nonrenewable resources, but not all nonrenewable recourses are fossil fuels. these resources are not being renewed as fast as we are using them. i hope this considering there weren't any answer choices.