Pick from:
1). Prepare the tile under the pressure of the vacuum. Take notice of if any of the tile is loose under pressure.
2). Check the levels on the floor to determine if the concrete is level. If it is not level, you will want to purchase self-leveling underlayment to create an even surface.
3). Do not use powder-based cleaners, as they can create strong fumes. Mix the concrete together in a wheelbarrow or a spray bottle.
4). Clean very firmly so as not to dislodge plaster or grit. Sand the surface of the concrete completely with a 600 grit sandpaper.Choose from options above and answer: What most naturally follows?

How to lay tile on concrete
Clean the surface of the concrete with a vacuum.
Follow up with a detergent, like tri-sodium phosphate (tsp). Make sure the area is well ventilated when you use this strong chemical cleaner.
Answer:
2).