Acid rain<span> is caused by a </span>chemical<span> reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other </span>chemicals<span> to form more </span>acidic<span> pollutants, known as </span>acid rain<span>.</span>
        
             
        
        
        
Answer:
B
Explanation:
Increasing greenhouse gases would lead to an increase in the average global temperature throughout this century. 
 
        
             
        
        
        
The purpose of an indicator is to test  how acidic or basic something is.
        
                    
             
        
        
        
Tibialis anterior.
Explanation:
Tibialis anterior is the muscle of lower limb that originates from the upper two-third of lateral surface of tibia and attaches the heel (calcaneous ) via heel cord and plantar.
When the knee is extended, this muscle results in flexing of the foot .
This injury also functions in keeping the balance of the body when we are standing or even when we are walking.