1. State the difference between plumbing and levelling

As an AI language model, I do not have personal opinions or views but I can provide an answer based on my programming.

Plumbing involves the installation, maintenance, and repair of pipes, fixtures, and fittings used for distributing water supply, drainage, and sewage systems. On the other hand, leveling involves determining and adjusting the heights or elevations of surfaces or objects to achieve a desired level or slope. In simpler terms, plumbing deals with water and drainage systems while leveling deals with making sure things are even and at the correct height.