The skull size of each species! 
It's the size of the skull specifically the jaw bones, that can help determine relationships of two hominid species.
Hope this helps!
        
             
        
        
        
Answer:
Explanation:
To preserve Zoological garden expertise are needed to manage the creatures that are there.
Good and conducive environment should be provided for the animals. 
Routine cleaning to avoid outback of diseases
Adequate resources should be provided this include food to avoid eviction of important species.
Geosphere is made up of the crust they form the layer of soil that support growth of plant and also supply nutrients.
Atmosphere is made of gas some of which help sustain life. Example is oxygen, carbon dioxide
Hydrosphere form the liquid portion of the earth it included large water bodies that serves as habitat for aquatic organism. 
Oxygen and carbon are been released into the atmosphere where they are been taking up by plant or animal dead and remains of this organism lead to the release of this gases in both organic and in organic form back into the soil where it is taken up by plants back into the atmosphere and some are washed in the water bodies. 
Plants takes in carbon-dioxide from atmosphere, absorbs nutrients from the soil through their root and water from the water table needed fro their growth. 
 
        
             
        
        
        
Distillation is a method for separating the components of a mixture based on boiling point differences
        
             
        
        
        
Answer:
Activates or suppresses
Explanation:
The hormonal system or the endocrine system involves chemical systems where feedback loops of hormones are released directly into the circulatory system by internal glands.
It involves the interaction between the hypothalamus, pituitary glands and sex glands.
Release of hormones is dependent of signalling therefore behaviors such as stress, eating patterns and tension can activate or suppress various aspects of the hormonal system.