a large area of land drained by a river

a channel of water made by humans for transportation or for crops

the scientific study of the relationships between living things and their environments

the study of the physical features and history of Earth; it answers questions about how Earth came to have its present shape and form

either of two halves of the earth

the distance between the equator and a point north or south on earth's surface

distance on earth's surface east or west of an imaginary line

a dense evergreen forest, mostly found in tropical areas, that receives a large amount of rain all year long

a group of living things that can mate with one another but not with those of other groups

having neither extremely hot nor extremely cold temperatures; milk weather

going or reaching across a continent

a large region of Earth that has a certain climate and certain types of living things

a climate that is warm to hot and moist all year

a region characterized by a severe lack of available water

a region characterized by light rainfall

living or growing in water (plants or animals)

living or growing in the mountains (plants or animals)

living or growing on land (plants or animals)

something that is gained by force

a discussion in which reasons are advanced for and against some proposition or proposal

people having no permanent home but moving from place to place usually in search of food or to graze livestock

when a country or a nation takes control of other lands, regions, or territories outside of its borders

freedom from the control or influence of others

strong attachment to a particular country, or nation

an action that a person does for someone else

something that is sent to another country to be sold

to bring in (merchandise, commodities, workers, etc.) from a foreign country for use, sale, processing, reexport, or services

the organized action of making of goods and services for sale

trading one thing for another without using money

the official money of a country

the condition of being without a job

the act of clearing a wide area of trees

a system of government by the whole population or all the eligible members of a state, typically through elected representatives.

a classless society in which all property is owned by the community as a whole and where all people enjoy equal social and economic status

political system in which most forms of property and resources are owned or controlled by the public or the state

using a language native to a region or country

the first people who lived in any region