Pottery must be in order to contain things—food or liquid—and so that it does not explode in the kiln.

"glazed"
Glazing is the process of covering a ceramic piece with glass allowing it to hold liquid (and food) without leaking. when left a small part of the ceramic not glazed allows the pottery piece to be fired in a kiln without exploding.

It's either -limiting factors or -scarce resources but i'd go with my first answer since the food and water are abundant they really aren't scarce

Photosynthesisthe process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.