C. Mutualistic relationship
Flowers and hummingbirds have a mutualistic relationship where both benefit. Flowers produce food in the form of nectar (sugar and water) to attract hummingbirds which, in turn, move pollen for the plant (pollination).
        
             
        
        
        
<h3><u>Answer;</u></h3>
Compressions
Rarefactions
<h3><u>Explanations;</u></h3>
- A wave is a transmission of a disturbance from one point to another, and involve the transfer of energy from the source to another point.
- Waves may be classified as longitudinal waves or transverse wave depending on the vibration of particles relative to the wave motion or mechanical and electromagnetic waves based on the material medium of transmission.
- <em><u>Sound waves are examples of longitudinal waves that are mechanical waves since they require material medium for transmission. Longitudinal waves involves transmission of waves such that the vibration of particles is parallel to the wave motion , creating compressions and rarefactions.</u></em>
 
        
        
        
Answer:
D. Use the polymerase chain reaction
Explanation:
Polymerase chain reaction (PCR) is a molecular technique used to make multiple copies or amplify  a particular DNA sample. This enables scientist conduct thorough genetic analysis on minute sample of DNA, simply by amplifying it to a large quantity.
The PCR machine is usually used to amplify DNA fragment. The DNA fragments undergo three major steps successively: denaturation, annealing and elongation
 
        
             
        
        
        
If i was u i would look it up thats what i would do
        
                    
             
        
        
        
Observation should come first. Check the other answers in case im mixing up a different method. False.