Countries engage in economic activities that are best suited to their technology.

Developed countries have a widespread manufacturing and service industries that provide a high standard of living.

In developing countries most people work in commercial farming.

Governments may impose punishing taxes that ban trade with another country.

Free trade agreements, such as GATT and NAFTA, remove trade barriers, so goods can flow frealy.

Wastes from oil tankers, industry, and agriculture can contribute to water pollution.

Scientists do not agree whether global warming may cause the ice caps to grow.

All living thins in an atmosphere depend on one another for survival.