A simple solution is basically two substances that are evenly mixed together, but the mixture is homogeneous. Meaning, you can no longer tell the two substances apart once they are mixed in solution.
This is because the solute dissolves in the solution.
A solute is the substance to be dissolved (sugar). 
The solvent is the one doing the dissolving (water).
As a rule of thumb, there is usually more solvent than solute.The amount of solute that can be dissolved by the solvent is defined as solubility.
        
             
        
        
        
The vacuole usually acts as storage for materials needed by the cell. 
        
             
        
        
        
They are closer to the earths core
        
             
        
        
        
Answer:
OptionA,   re heard as a high pitched click when the valve should be—but is not—wide open during systole.
Explanation:
Heart murmurs are sound that are heard when the blood flow into the left ventricle but the flow get reduced as compared to the normal flow. The flow reduction happens because of the stenotic valve which has a narrow opening as compared to the opening in valves of a normal heart. Due to reduced valve size, the blood flow becomes fast and turbulent thereby producing murmur sound.
Hence, option A is correct
 
        
             
        
        
        
The smallest unit is species