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A ray is a part of a line that has one endpoint and goes on infinitely in only one direction. You cannot measure the length of a ray. A ray is named using its endpoint first, and then any other point on the ray 
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Answer:
The activation energy must be reached. The catalyst makes lower energy pathways available.
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<span>If sea level rises slowly, the reef might build upward. If sea level rises too quickly, the reef could die.</span>
        
             
        
        
        
<span>Tropics
A lot of rain falls there, so the possibility of acid rain and smog which can be carried by warm humid air can also form. </span>