not causing any damage to the environment

the animals, birds, insects which live in their natural surroundings and are not domesticated

to make something dirty or harmful by putting something dirty or harmful into it

energy which is able to be used for a long time without causing damage to the environment

the natural surroundings in which plant or animal usually lives

a situation that gets worse and worse in a way that cannot be controlled

a chemical substance that is used to kill pests, especially insects which are considered harmful to crops

a place where waste material is buried under layers of earth, often being excavated especially for this purpose

a substance designed to kill plants

waste material in the form of liquid discharged from a sewage works, factory and others

a kind of energy which is obtained from the sun's rays

all the living creatures and plants in a particular area, together with their environment or habitat, often considered in relationship to each other

a result or goal which you are trying to achieve