person authorized or employed to act on another's behalf.

measure of the amount of crops produced compared to the amount of time, effort, and money put into growing the crops.

to keep records or documents.

large mass of snow and other material suddenly and quickly tumbling down a mountain. Read more in the NG Education Encyclopedia

(web log) website that contains online personal reflections, comments, and often hyperlinks provided by the writer.

high-speed data transmission or communication where the bandwidth is shared by more than one signal.

characteristics of a specific environment, especially as they impact human beings.

a way to understand a topic or area using spatial features and relationships.

process by which glaciers melt faster than precipitation can replace the ice.

to list or evaluate.