<em>Hardness is a measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied</em> <em>Macroscopic hardness is generally characterized by</em> <em>strong intermolecular bonds</em>, <em>but the behavior of solid materials under force is complex; therefore,</em> <em>there are different measurements of hardness</em>: <em>scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and super hard materials, which can be contrasted with soft matter.</em>
 
        
             
        
        
        
Answer: Using tissues that would have been disgarding after surgical procedure
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. 
 
        
             
        
        
        
Based on the CDC Article There were about 300 species of birds infected by the west Nile virus in Florida. good luck:)
        
             
        
        
        
White Blood cells Because they are produced in your body and they are constantly used more than they are replaced