Answer:
It contains 2 or 3 ppm of oxygen concentration. 
 
        
             
        
        
        
most common to least common favorite
 
        
             
        
        
        
Answer:
Increase in eosinophils.
Explanation:
The leukocytes are the white blood cell that plays an important role in the immune system. The white blood cell include eosinophil, basophil, neutrophil and monocytes.
The allergic reactions that are caused by hay fever or asthma is marked by the excess increase in the number of eosinophils in the body. The eosinophils are the first to reach at the site of parasitic infections and protect the body during the allergic reactions. 
Thus, the answer is eosinophils.
 
        
             
        
        
        
The answer is 5 hope this helps you have a great day 
 
        
             
        
        
        
Answer:
By the numbers, humans produce a lot of food—enough to provide every person on Earth 2,750 calories per day, exceeding almost all dietary recommendations.
There’s one glaring problem, however: Humans aren’t producing enough of the right food.
When researchers at the University of Guelph in Canada broke those calories down into different food groups, they found a shortage in production of the most important foods. In the long run, with the global population expected to balloon to about 10 billion people by mid-century, this could cause some serious problems.
Explanation: