The answer is B, because sound waves vibrate through mediums (such as liquids, solids, and gas). It can’t travel through a vacuum because there would be no molecules to vibrate.
        
             
        
        
        
Among the options, lupus can be the best answer. Lymphatic diseases can affect one's lymph,nodes and lymph vessels. Lupus is a systemic autoimmune disease occurring when one's immune system attacks one own tissues as well as organs. It can affect different systems in the body.
        
             
        
        
        
Answer:
Scientist count the world humans population with an organization called The United Nations Population Division (UNPD), 
Explanation:
Which keeps track of the world population, projects that the world's human population will hit 7 billion on Halloween Day 2011. Admittedly, that is just an estimate: There's no way to know exactly how many people are alive at any given moment, and the true date that humanity's ranks will surpass 7 billion could come in the weeks or months before or after Oct. 31. Nonetheless, the UN's guess is the best there is.
 
        
             
        
        
        
The proteins exhibit four levels of organization:  
1. Primary structure: It refers to a sequence of amino acids join together by the peptide bonds to produce a polypeptide chain.  
2. Secondary structure: It is a localized twisting of the polypeptide chain by producing a hydrogen bond. Two types are formed, that is, the alpha helix and beta pleated sheet.  
3. Tertiary structure: It refers to the three-dimensional composition of a polypeptide chain. The folding is not regular as it is in secondary composition. It produces ionic bonds, hydrophobic interactions, disulfide bond, and hydrogen bond amongst the polypeptide chains.  
4. Quaternary structure: It comprises an amalgamation of two or more polypeptide chains that functions as a single functional unit. The bonds are identical as in tertiary composition.  
Thus, the levels of secondary, tertiary, and quaternary protein structure would get affected if all the hydrogen bonding associations were inhibited.