Answer:
The oblique illumination is
used by the microscopists to resolve N. Spencrii in the Dark Field Condensers.
Explanation:
It was found that the use of oblique light was required to resolve the striae. Oblique illumination was the first step toward dark field microscopy. In dark field, light 
seems to radiate from the specimen while all the rest of the field is black. Resolution is as good as that in bright field while contrast is enhanced.
 In dark field microscopy, no 
direct light from the condenser enters the objective lens. Only light 
that is reflected, refracted or diffracted by the specimen enters the objective. The dark field condenser produces a circle of light. The 
light is at an extremely oblique angle to the surface of the slide. This 
oblique light comes to a focus on the specimen. It then diverges so 
strongly that no direct light enters the objective. This type 
of illumination is a hollow cone of light.
 
        
             
        
        
        
Answer:
In the United States, the two major layers of government are at the state and national levels. This system, where more than one layer of government has jurisdiction over the same territory, is called federalism. Although it seems natural to US citizens that government is divided into multiple layers, in fact, there are only 15 federal republics in the world.
In the United States, the federalist system emerged because the states evolved from separate colonies, which had diverse populations and different needs. The Framers of the Constitution envisioned that state governments, not the national government, would be the main unit of government for citizens on a day-to-day basis.
Explanation:
 
        
                    
             
        
        
        
Syrian migrants and their descendants who, whether by choice or coercion, emigrated from Syria and now reside in other countries
        
                    
             
        
        
        
Answer:c. Learning .
Explanation:
Learning as related to psychology explains how environment and experience affects the behavioral pattern of a person or animal.