Task: Question Answering
Input (English): Process:  -Sunlight passes through the glass into the greenhouse -The plants and floor absorb the the sunlight -The absorbed sunlight is converted to heat -The heat cannot escape the glass -The heat is trapped in the greenhouse -The hot air rises -The colder air at the top is pushed to the bottom -The colder air is then warmed by the floor and the plants.
 Question: What is the effect of the air pressure drops on the sky is filled with darkness.?
Output (English): none