Answer:
 External respiration: CO2 diffuses into the blood
Explanation:
External respiration is also called the pulmonary gas exchange. It refers to the diffusion of O2 from the air in the alveoli of the lungs to blood in pulmonary capillaries and diffusion of CO2 in the opposite direction from the capillary blood into the alveolar air. External respiration in the lungs is responsible for oxygenation of deoxygenated blood coming from the right side of the heart. The oxygenated blood is then returned to the left side of the heart.  
 
        
             
        
        
        
Answer:  Louis Pasteur
Louis Pasteur in 1860s, proposed germ theory. The theory was based upon the fact that diseases are caused by the microorganisms. He was officially the first to publish his work.
 
        
             
        
        
        
The correct answer is option eosinophil: bacterial macrophage
Eosinophil is responsible for  defense against parasitic infections and few are involved in organ formation.
 
        
                    
             
        
        
        
I think that the answer is C- "I RNA contains uracil and ribose." because it is the one that mostly makes sense and is the one that most shows the difference between RNA from DNA. 
According to google: "Ribonucleic acid (RNA) is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the three major macromolecules essential for all known forms of life."
I hope this helped!