1. Heat olive oil in a skillet over medium heat. Add shrimp, chili powder, cumin, garlic powder, salt, and pepper. Cook until shrimp is pink and cooked through, about 5 minutes.
2. In a mixing bowl, combine cooked rice, black beans, corn, and salsa.
3. Warm tortillas in a dry skillet or microwave.
4. Assemble burritos by placing a portion of the shrimp mixture, rice mixture, shredded lettuce, and cheese onto each tortilla. Roll up and serve.