1. what are the three main types of signals can cells receive?

Paracrine signaling autocrine signaling endocrine signaling and signaling by direct contact

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 : ) 

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it