Answer:
This graph is showing how different rates of light intensity, environmental temperature, and Carbon dioxide affect the rate of photosynthesis. It looks like the greatest rate of photosynthesis has .13% Co2 at 30 degress celsius. 
Explanation:
I was always taught that they y-axis is the dependent variable and going off that, all the other variables can be controlled and changed. 
 
        
             
        
        
        
The correct answer is<span> a. Volcanic glass
Volcanic glass is also known as Obsidian. It is formed when lava cools down too rapidly and crystals grow minimally, without grains.</span>
        
             
        
        
        
Look it up on google , i had this same question and google helped me. i can’t remember the answer or i’d tell u
        
             
        
        
        
None of the above? I’m guessing, secondary, primary and tertiary doesn’t sound right !
        
             
        
        
        
Answer:
elements of a civilization
Explanation:
idk