At his first show in LA for 10 years, Chappelle charges straight into the fire with bits on Bill Cosby, O.J. Simpson, and his own brushes with controversy. 阔别洛杉矶10年后的首秀，查贝尔借用调侃Bill Cosby，O.J Simpson和自己过往的风波，直接了当地将现场推向高潮。
Dr Helen Czerski examines the world of sound waves.
