Спереводом. resources may be defined simply as those naturally occurring riches of the earth that can be exploited to the benefit of mankind. the ability to identify and use resources was what distinguished mankind from other animals. the discovery that flint could be shaped to perform particular tasks made flint a resource and led to an active search for flint deposits. the history of mankind has been punctuated by the discovery and exploitation of new resources. timber was probably the first resource used by mankind. primitive digging tools and weapons could be made out of pieces of wood. the discovery of stone tools led to major advances in the hunting habits of people. the stone age was succeeded by the bronze age when most weapons were made from bronze. by the time of ancient greek civilization iron had replaced copper and bronze. this period is known as the iron age. the invention at the beginning of the 18th century of new machines driven by steam led to huge demands for raw materials. coal became the principle source of energy both driving steam-engines and smelting iron ore. iron was needed to build both the engines and the machines. coal and steel were the dominant industries until the early part of the 20th century when cheap and plentiful oil began to replace coal as an energy source. but people must remember that almost all the resources are non-renewable.