B.) A dog walks to a stream and drinks when it gets thirsty  
would have to be your answer..
        
             
        
        
        
Answer:
The correct answer is A. Tobacco mosaic virus 
Explanation:
Virus can have DNA and RNA as its genetic material. Tobacco mosaic virus has RNA as its genetic material. Protein is not a genetic material because it is a product coded by genetic material.  
So a hybrid can be made only when the genetic material of two different organisms is mixed not two different biomolecules. Therefore when RNA from the tobacco mosaic virus is mixed with the protein from a DNA virus the result would be a tobacco mosaic virus only. 
 
        
             
        
        
        
Answer:
a) the oxidizing agent.
Explanation:
In the citric acid cycle, malate is dehydrogenated into oxaloacetate and the reaction is catalyzed by malate dehydrogenase. The released electrons are accepted by NAD+. So, NAD+ is reduced into NADH. The substances that accept electrons during chemical reactions and are reduced to oxidize the other substances are called oxidizing agents. NAD+ serves as an oxidizing agent as it accepts electrons to oxidize malate into oxaloacetate.
 
        
             
        
        
        
All of about is the answer