【简答题】Cars are an important part of life in the United States. Without a car most people feel that they are poor. And even if a person is poor he doesn't feel really poor when he has a car. Henry Ford was t...
【单选题】A 20-year-old, previously healthy man is jogging one morning when he trips and falls to the ground. He suddenly becomes markedly short of breath. On examination in the emergency room there are no brea...