production and discharge of something. A substance (e.g. gas) released into the air.

covering or submerging of normally dry land with large amount of water. (Of liquid) to fill or cover something completely.

Whether it is raining, sunny, cold etc. outside. To erode or become damaged due to the environment.

1000s.

action of one object striking another. Acts or forces of one thing hitting something else. To hit or strike someone or something with force.

How hot or cold something is, e.g. the weather.

Line of text indicating what a passage is about. To lead or be responsible for something.

The task of making a place clean. To remove the inner parts of an animal.

change resulting from cause. Changes brought about by a cause; results. cause something to happen.

By a large amount and very suddenly.

A country in central Europe, on the Baltic Sea in the north; population 80,700,000 (estimated 2015); capital, Berlin; official language, German..

Greenhouse gas that makes the Earth get warmer. Glass building used for growing plants.

flying or rising high in air. To fly or rise high in the air.

Having power or authority.

person who is studying or has expert knowledge of one or more of natural or physical sciences. People who are trained in a science.