Answer:
Environment plays an important role in living and the existence of life on earth. Earth is a home for many living species and we all are dependent on the environment for food, air, water, etc.
Explanation:
 
        
             
        
        
        
Answer:
Oxygen 
Explanation:
The earth has been divided into three major categories crust, mantle, and core which are further segregated into sub-parts. Since the crust is the outermost layer of the shell, the outer crust of the earth consists of a combination of silicon and oxygen in the majority followed by some percentage of other metals as well. <u>The percentage of Oxygen includes nearly 50% i.e. 46.6% followed by 27.7% of Silicon and the other 25.3 % includes aluminum, iron, sodium, magnesium, etc</u>. Thus, '<u>oxygen</u>' is the correct answer.
 
        
             
        
        
        
I’m not sure but try Russia and América hope it helps let me know if I’m wrong:)