Answer:
Compressions and Rarefactions
<em>A vibrating tuning fork is capable of creating such a longitudinal wave. As the tines of the fork vibrate back and forth, they push on neighboring air particles. The forward motion of a tine pushes air molecules horizontally to the right and the backward retraction of the tine creates a low-pressure area allowing the air particles to move back to the left.</em>
Explanation:
These regions are known as compressions and rarefactions respectively. The compressions are regions of high air presure while the rarefactions are regions of low air pressure.
<em>Sound waves can also be shown in a standard x vs y graph, as shown here. This allows us to visualise and work with waves from a mathematical point of view. The resulting curves are known as the "waveform" (i.e. the form of the wave.) The wave shown here represents a constant tone at a set frequency.</em>
 
        
             
        
        
        
Both are methods of viral multiplication inside the host cell.
 Lytic cycle (which is more common) includes steps like: 
<span>1. Infection of the host cell-virus attaches to the receptor of the host cell, penetrates it and releases its genetic material into the host cell.</span> 
<span>2. Virus Multiplication-Virus incorporated its genetic material into the host’s and uses its metabolism to multiply. Viral genetic material replicates separately from the host DNA.</span> 
<span>3. Cell Destruction-  Virus releases an enzyme that breaks the cell wall from within, thus destructing the host cell.</span>   
<span>Lysogenic cycle also includes steps of infection, penetration and incorporation of the genetic material. But, after the virus integrates its genetic material it becomes dormant, letting the host multiple and continue its normal activities. Viral genetic material replicates within the host DNA during the host cell's division, so the daughter host cells are infected too.<span> At some point, the virus is triggered, it multiplies and ultimately, destroys the host cells.</span></span>
        
             
        
        
        
Answer: space or shelter, ability to reproduce 
Explanation:
 
        
             
        
        
        
Since people with HIV have weakened immune systems it would be:
C) People with HIV are unable to fight off these rare diseases.