float|verb|to be on water without sinking; to move or be moved gently on water or through air
control|noun|the ability or power to make someone or something do what you want
control|verb|to decide how things are organized and managed; to limit the spread of something; to have the power to make someone or something do what you want
pollute|verb|to release dangerous or unpleasant substances into the air, soil or water
difficult|adjective|not easy; requiring a lot of work or skill to do or make 
edge|noun|the line where something ends or begins
