A perfectly competitive industry is initially in a short-runequilibrium in which

A perfectly competitive industry is initially in a short-runequilibrium in which all firms are earning zero economic profitsbut are operating below their minimum efficient scale. Explain thelong-run adjustments that will create equilibrium with firmsoperating at their minimum efficient scale. Why is a perfectcompetitive firm associated with efficiency for both consumers andbusinesses? (around 250 words is fine)