Answer:
Exosphere -The exosphere layer is mainly composed of extremely low densities of hydrogen, helium, and several heavier molecules including nitrogen, oxygen, and carbon dioxide closer to the exobase. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another.
Thermosphere - The aurora (Northern Lights and Southern Lights) mostly occur in the thermosphere. The thermosphere is a layer of Earth's atmosphere. The thermosphere is directly above the mesosphere and below the exosphere. ... Temperatures in the upper thermosphere can range from about 500° C (932° F) to 2,000° C (3,632° F) or higher.
Mesosphere- Most meteors burn up in the mesosphere. A type of lightning called sprites sometimes appears in the mesosphere above thunderstorms. Strange, high-altitude clouds called noctilucent clouds sometimes form in this layer near the North and South Poles.
Stratosphere-The stratosphere is the second major atmospheric layer above the troposphere, extending in altitude from about 8 to 30 miles high. No weather occurs in the stratosphere. The statosphere contains over 15% of the total mass of the atmosphere, and is where the ozone layer is located.
Troposphere-The troposphere is the lowest layer of Earth's atmosphere, and is also where nearly all weather conditions take place. It contains 75% of the atmosphere's mass and 99% of the total mass of water vapour and aerosols.
i hope this helps, good luck :) 
 
        
             
        
        
        
If a person is shot, and the bullet destroys the part of the brain called the medulla, which maintains basic life functions (heart rate, breathing), there is virtually no chance for surviving that injury
        
             
        
        
        
Each chromosome contains one molecule.
        
             
        
        
        
Answer:
C
The while reason we wash fruits and vegetables before consumption is because we need to wash off the pesticides 
 
        
                    
             
        
        
        
The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.