Valence shell
The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms. This outermost shell is known as the valence shell, and the electrons found in it are called valence electrons.
        
             
        
        
        
Answer:
Flat terrain/Same moisture.
Explanation:
This option seems to make the most sense.
 
        
                    
             
        
        
        
A population....... I think
        
                    
             
        
        
        
Answer:
They had a large brain size of 700 to 1,250 cubic centimeters and large brow ridges with a nuchal torus at the back of the skull.
Explanation:
<em>Homo erectus</em> was one of the species of the homo genus which were considered the first species to have the human-like the feature that is they can stand upright on two legs and were therefore referred to as the upright man.
They showed many evolutionary advances over their ancestors called Homo Australopithecus as they showed encephalization. Encephalization refers to the increase in the size of the brain due to more neuronal complexity and neurogenesis and they possessed about 750 to 1250 cc brain size.
They showed torus at the back of the muscle which can hold the muscle of the neck and also showed the large brow ridges in the front of the skull.
Thus, the selected option is the correct answer.
 
        
             
        
        
        
I think that for 1 it’s either A or B as the kidneys and everything get air and the lungs release it.
For 2 is probably D as the others don’t really make much sense.