通读全文，根据短文内容的理解，选择最佳答案填空。
Early in the morning, at noon, or in the evening in big cities and in the countryside, all over the United States, you can see Americans running—men and women, young and old. People run1 — along the beaches of California, 2 Central Park in New York, down quiet streets in small towns or at the gym. Some people even run in 3 living rooms.
Running wasn't so popular in the past. In the 1960s, runners were mostly athletes and healthy strong people. When people saw a runner, they used4, "Hey, what's the hurry for?" or they might say to 5 , "Is he crazy?" At that time, women almost never ran. If they did, they might be laughed at. But today all these have6. Men and women of all 7 enjoy running.
Doctors say many of the health problems in the United States 8these bad habits: eating too much, smoking cigarettes, and taking 9 exercise. Doctors tell us, "Eat less, don't smoke, and exercise more." Running is good exercise10 it helps build strong hearts and lungs. It also helps most people lose weight.
