Coal-burning factories and increased automobile usage has caused the greatest increase in which of these?

The continental divide a divides the united states into east and west b. divides the united states into north and south c. divides the flow of river systems in the united states into east and west d. is a series of rivers and mountains that separates canada from the united states select the best answer from the choices provided.

What body of water is the second cataract of the nile river submerged under

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!