not expensive

happening once every year, or relating to a period of one year

a part of a building or piece of land used for a particular purpose

to be helped by something or to help someone

the number and types of plants and animals that exist in a particular area

to make something happen, especially something bad

something that is difficult and that tests someone's ability or determination

the way the Earth's weather is changing

the result of a particular action or situation, especially a bad result

a period of ten years, especially a period such as 1860 to 1869, or 1990 to 1999

when all the trees in a large area are cut down

something which makes a situation more difficult, or makes you less likely to succeed

something that causes great harm or damage

a long period when there is no rain and people do not have enough water

the result of a particular influence

when gas, heat, light, etc. is sent out into the air, or an amount of gas, heat, light, etc. that is sent out

the air, land and water where people, animals and plants live

not harmful to the environment

when soil, stone, etc. is gradually damaged and removed by the sea, rain, or wind

a large amount of water covering an area that is usually dry

a fuel such as coal or oil that is obtained from under the ground

a large mass of ice that moves very slowly, usually down a slope or valley

a gradual increase in world temperatures caused by polluting gases

when cows or other animals graze, they eat grass

a building made of glass for growing plants in

a gas that causes the greenhouse effect, especially carbon dioxide

the quality of being hot or warm, or the temperature of something

a subject or problem which people are thinking and talking about

continuing a long time into the future

someone who disagrees with an action or belief and tries to change it

to make water, air, soil, etc. dirty or harmful

o say that an event or action will happen in the future, especially as a result of knowledge or experience

to give someone something that they need

to make something less

a particular area in a country or the world

to take something away

the possibility of something bad happening

the answer to a problem

to cover or reach a wide area