13 is the answer its so easy
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A combination of two or more metals is called and Alloy.
Explanation:
Temperature is the amount of heat energy contained in the air, and we measure this in degrees. Air pressure is the amount of pressure exerted by the air in a particular air mass. Humidity is a measure of the water content of the air mass. Clouds are tiny drops of water or ice that form in the atmosphere.
<span> Biological disadvantages; people will be able to rid themselves of diseases or provide themselves with superior genes. </span>
An object is in motion if its distance relative to another object is changing. To tell if an object is moving, you use a reference point. If an object's distance from another object [reference point] is changing. A place or object used for comparison to determine if something is in motion.
I'm not too sure if this is what you needed go know, I hope it helped