None...........................probably mars
The troposphere has the highest density.
Explanation:
Echolocation is one of the methods of orientation mainly used by the microchiropteran or insectivorous bats. While flying, these bats emit high frequency ultrasound. These sound pulses hit obstacles like rocks, trees, walls etc. and their echoes are heard by bats.
Photosynthesis
During photosynthesis, plants use sunlight, water, carbon dioxide to create energy and oxygen gas is liberated as a by-product of this process. Sunlight: Sunlight also produces oxygen. Some oxygen gas is produced when the sunlight reacts with water vapour in the atmosphere.
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