Final answer:
Premolars have flat crowns with rounded cusps for mashing foods, canines are sharp teeth for tearing up food, and molars have pointed cusps for crushing food.
Step-by-step explanation:
The premolars have flat crowns with prominent ridges called cusps that are used to crush and grind ingested materials. They have an overall flatter shape with two rounded cusps useful for mashing foods. The canines, on the other hand, are sharp, pointed teeth used for tearing up food. Finally, the molars have several pointed cusps used to crush food until it is ready for swallowing.