Answer:
Chitin is a long-chain polymer derived from glucose. It strengthens cell walls of fungi and the outer covering (exoskeleton) of arthropods (including crabs, shrimps, and insects).
Explanation:
 
        
             
        
        
        
Answer:
A
Explanation:
Coal is majorly used to produces electricity. The coal is ignited and the heat produced used to heat water to steam. The steam is then used to drive turbines with a dynamo effect to produce electricity. Turning off lights when not in use reduces the demand for electricity hence reducing the amount of coal needed to meet this demand. 
Other ways to conserve energy is using bulbs with low energy demand - such as LEDs - and  improving natural lighting indoors. 
 
        
             
        
        
        
It should be transport of waste but I’m not 100% sure :(
        
             
        
        
        
Answer:
The correct answer is: a pH 2 solution has a <u>10000 times</u> greater hydrogen ion concentration than a pH 6 solution.
Explanation:
The pH scale is a measurement used to describe the acidity of a solution, and this acidity is given by the concentration of H+ (hydrogen ion) in said substance. A solution with a greater concentration of H+, is more acid than a solution with a smaller concentration of H+ and, therefore, has a lower pH. Given that the pH scale is a negative logarithmic scale, a solution with a pH of 3 has a ten times greater H+ concentration than a solution with a pH of 4. 
A pH 2 solution has 10 times more H+ ion concentration than a pH 3 solution, 100 times more H+ ion concentration than a pH 4 solution, 1000 times more H+ ion concentration than a pH 5 solution, and 10000 times more H+ ion concentration than a pH 6 solution.
 
        
             
        
        
        
The Metric System units are milliliters and liters<span>. </span>