90 mammal species become extinct in the period 1901-2000 than became extinct in the period 1801-1900.
Extinction is a situation in which something no longer exists. Their can be many reasons associated like species have been hunted to the point of extinction, scarcity of food or natural disasters.
Their are two main types of extinction firstly Mass extinction that has occurred only five times in history. The other is Background extinctions which occurs over longer period of time and are considered important in natural extinction rate.
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I think the kind of choices would be primary or secondary source: and this would be a secondary source: 
a primary source would be the journals where the results were published and the secondary would be the tv program that used those reports as a primary report!
so the answer is secondary source!
        
                    
             
        
        
        
Adenosine triphosphate or ATP is a compound that stores and provides the energy required to perform a variety of biochemical processes in living beings.
After being consumed, it losses one or two of its phosphates and becomes adenosine diphosphate (ADP) or adenosine monophosphate (AMP).
It can also act as a coenzyme and be a precursor to DNA and ARN because it is a nucleic acid.
Each molecule of ATP is a nucleoside triphosphate, formed by an adenine (a nitrogenous base), a ribose (a sugar), and triphosphate.
This means the correct answer is A) nucleic acid
 
        
             
        
        
        
Answer:
The purpose of colorful petals is to attract insects