Greek Pasta Salad I

½ cup olive oil

½ cup red wine vinegar

1 ½ teaspoons garlic powder

1 ½ teaspoons dried basil

1 ½ teaspoons dried oregano

¾ teaspoon ground black pepper

¾ teaspoon white sugar

2 ½ cups cooked elbow macaroni

3 cups fresh sliced mushrooms

15 cherry tomatoes

halved

1 cup sliced red bell peppers

¾ cup crumbled feta cheese

½ cup chopped green onions

1 (4 ounce) can whole black olives

¾ cup sliced pepperoni sausage

cut into strips