Answer:
Different brands of nail polishes used by Sarah.
Explanation:
While conducting an experiment two different variables are considered namely dependant variable and independent variable. The variable which is continuously changed to see the effects is called as independent variable and the variable which is being tested is called as dependant variable. 
In the given scenario, Sarah want to know best brand of nail polishes which lasts longest without chipping. Thus the different brands of nail polish used by her is considered as independent variable.
 
        
             
        
        
        
Answer:
b because I learned it in 4th grade
Explanation:
b
 
        
             
        
        
        
<span>Olfactory glands coat the olfactory epithelium with a pigmented mucus. They are responsible for the olfactory information, which is a term that describes the smell . </span>Olfactory information is first received by the cerebrum. <span>The </span>cerebrum is a large part of the brain, <span>the uppermost region of the central nervous system </span><span>that is responsible for olfaction, or the sense of </span>smell.
        
             
        
        
        
If DNA read A-T-T-A-C-G-G-C-C the RNA would be U-A-A-U-G-C-C-G-G
DNA replication is important because new cells require their own strand of the DNA. Without replication, there would be no new organisms because the DNA’s information would not be passed on.
 
        
             
        
        
        
Answer:
b) In allosteric regulation, a small molecule binds to a large protein and causes it to change its shape and activity.
Explanation:
Allosteric regulation refers to the activity control of an enzyme by binding small molecules to regulatory sites on It. This binding causes an alteration of the protein conformation and consequently the shape of the active site and its catalytic activity are altered. Regulatory enzymes can act by either stimulating or inhibiting the activity of a protein.