In a 4-quart pot stir together undrained tomatoes, water, beans, tomato sauce, chili powder, oregano, and pepper. Bring to boiling; reduce heat. Cover and simmer 10 minutes. Using a potato masher, mash beans slightly. Stir in the corn and zucchini. Return to boiling; reduce heat. Cover and simmer 10 minutes more or until vegetables are tender. Spoon into serving bowls. Top each serving with 2 tablespoons cheese. Makes 6 servings.