Commercial jets fly in the lower stratosphere. what happens to thhe exterior temperature of these planes as they leave the stratosphere and return to the ground

The external temperature of these planes decreases and then increases as they leave the stratosphere and return to the ground.  

This occurs as the airplane initially goes up via the troposphere while traveling through this layer, the temperature of the plane decreases as they go higher. However, when the plane goes into the frontier between the troposphere and the stratosphere, that is, the tropopause, the temperature elevates.  

This increase in temperature is a result of the ozone layer that is present in the stratosphere and absorbs the UV rays from the Sun, making an elevation in temperature.  

b. the carbon cycle ensures living things have a source of hydrogen

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.