Natural resources are the useful things that occur (36) __________ in the environment. Some examples we oil, water and trees. Humans use natural resources for every part of their lives, so we all must be careful to use them wisely.

Resources can be divided (37) __________ renewable and non-renewable resources. The difference is whether the resource recovers naturally over time. Renewable resources are usually living things like or plants. For example, trees are a renewable resource because they grow soon again after we cut them down. But oil is a non-renewable resource because it takes millions of years (38) __________ again. We must try to save the non-renewable resources because once they are used up, we cannot get more. Natural resources can be traded between countries. They can create (39) __________ wealth for resources rich countries. For example, Saudi Arabia, Iran, and Kuwait in Middle East have a large amount of petroleum. They (40) __________ it to other countries and make good money.

Natural resources are the useful things that occur (36) __________ in the environment.