What is ecology? This word comes from the Greek word  which means "house". So this word means scientific study of the relationships that living organisms  have with each other and with their environment. Nowadays we speak about ecological problems, because of the technology. There are too many machines which pollute the air, water and ground. Fishes cannot live in dirty water. birds cannot fly in dirty sky. trees are cut. Animals cannot live in forests without trees . People breath dirty air, eat unhealhy food and have many deseases. That is ecology. Scientists make their best to improve this situation. They are called ecologists. Many voluntary groups such as Greenpeace try to help our planet.