THE years from 1920 to 1929 in the US are often called the Roaring (狂野的) '20s. World War I had recently ended, and people just wanted to have fun. Everyone danced wild new dances, such as the Charleston (一种两手交叉放在膝上的舞蹈), and listened to a wailing (哀泣的) new music called jazz. "Talkie" movies replaced silent films. People flocked to theatres to see them. At home, they listened to an exciting invention called the radio...