Question

what is the \job\ that our posterior teeth performs?
grinding down and pulverizing food particles
chopping into food
helping with our speech
none of the answers are correct

Explanation:

Posterior teeth, like molars and premolars, have broad surfaces designed for grinding and pulverizing food to aid in digestion. They are not mainly for chopping (front - teeth are more involved in that), nor for speech.

Answer:

grinding down and pulverizing food particles