the physical surroundings that plants, animals,

and humans live in

the continuous movement of water between

earth and sky

a rule or law that limits something.

a natural or human-made lake where water is

stored.

a way to supply water to land or crops.

done deliberately

in a way that is important or large enough to

make a difference.

happening over a large area or to many

people.

a shortage of food that may cause people to

starve.

to use up so that there is little left.

to help bring about a result; to play a part in an

outcome

made polluted by adding something

harmful.

enough for a specific need. An adequate

amount of sleep for me is seven hours each night.

the removal of dirty or hazardous substances

carrying out effectively

the typical and repeated way that something

happens.

a person who is forced to leave his or her home

due to disaster or war.

to become dry and shriveled.

causing destruction or ruin