The velocity of a stream usually increases downstream. The gradient (slope) of the stream typically decreases but gravity, elimination of bed roughness and an increase in the amount of water from the entry of tributaries tends to increase the velocity.
Answer
Bob described the mesosphere and Joe described the asthenosphere.
Explanation
The three layers of earth are uppermost crust, middle mantle, and an innermost core.
The mantle of the earth has semifluid asthenosphere that is present below the lithospheric mantle. The rocks are in the semi-molten stage due to the higher temperature and pressure conditions.
The deepest part of the mantle is the mesosphere. Hence, Bob described the mesosphere and Joe described the asthenosphere.
What is your problem what subject
Photosynthesis is the process by which plants turn light energy into chemical energy to keep their cells healthy. They also need carbon dioxide (CO2) and water (H2O) along with light to complete the process.