Answer:
Here's what I get  
Explanation:
Per the above explanation, pH means "power of hydrogen ions."
The concentration of hydrogen ions is a measure of the acidity of a solution. A higher concentration represents a more acidic solution.
The definition of pH is
pH = -log[H⁺]
Thus, pH is a measure of the hydrogen ion concentration.
The more negative the pH, the greater the Potenz of hydrogen ions.
 
        
             
        
        
        
Answer:
Explanation:
It is called a double circulatory system because blood passes through the heart twice per circuit. The right pump sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart. The left pump sends the newly oxygenated blood around the body.
 
        
             
        
        
        
Answer:
the sun 
Explanation:
The typical lunar eclipse happens when the Sun, Earth and moon are all aligned 180 degrees apart from each other in the sky. When this happens, the Earth casts a shadow onto the moon, so the Sun should not be visible at all if you can still see the moon.
 
        
                    
             
        
        
        
Ultraviolet sun rays it damages the cells and can cause skin cancer.