How are rivers made ?

Rivers usually begin in upland areas, when rain falls on high ground and begins to flow downhill. They always flow downhill because of gravity. They then flow across the land - meandering - or going around objects such as hills or large rocks.

Explanation:

Hope this helps!

A river is created when water moves from higher elevation to lower elevation. It usually goes downhill, and can join with other rivers. The river ends when it flows into an ocean.

I hope this helps!

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c