In flies, long wings are a dominant trait, and short wings are a recessive trait. if a heterozygous long-winged fly is crossed with a short-winged fly, what is the likelihood that the offspring will contain the recessive allele?
a) 0%
b) 50%
c) 75%
d) 100%

What is the question? if you were looking to design a method of separating something, you can separate this compound by putting both in water and allowing the water to dissolve the sugar. then pour it into another beaker and evaporate it then boom! salt and sugar : ) 

Icant be totally sure but i would say with confidence that it is example #1 about cells.

Compound light microscope