What is the word used to describe the change in elevation for a given stream or river over a horizontal distance

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

In what three areas is the us leader?

Which statement is an accurate description of life in mongolia in recent years? the majority of the population now lives in cities. after a brief period of democracy, communists regained control of the government. subsistence farming remains the primary economic activity in the country. relations between mongolia and china are now tense. -gradpoint