2. If a ball is rolling, it should roll forever unless acted upon by an outside force. Of course, a rolling ball never seems to be in danger of rolling forever. That force is called .

Andra has a family history of osteoporosis. her doctor advises her to eat foods rich in calcium. which foods should she add to her diet? a. fruits, especially grapes and berries b. unsaturated fats like olive and soybean oil c. beet greens, broccoli, and cheese