Plz help with this chemistry question?

You are given three liquids. One is a pure substance, and the second is a solution of 2 miscible liquids. the third is a solution composed of a solid solute in a liquid solvent. Describe what procedure you would go through to distinguish between the three solution. I think that for the solution with the solid solute, we shoud heat it, to see if it leaves a residue behind, but i am not sure for the other 2