阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。
German doctors have warned that headbanging(随音乐猛烈摇头晃脑) could be bad for you. Headbanging is a dance from heavy metal music. Dancers shake their heads backwards _____ forwards, from side to side, very _____(quick). Doctors say the dance could lead to brain injury. They once _____(treat) a 50-year-old heavy metal fan. His headbanging led to brain damage. The man had no history of head injuries but had been headbanging for many years. The doctors say the risk of brain damage from headbanging _____(be) low, so heavy metal fans _____ not need to stop doing the dance.
The man had bad headaches _____ going to a concert. He had a brain scan at a hospital. Doctors found bleeding inside his brain. He had an _____ (operate) to repair the damage. Doctors drilled a hole in his brain _____(release) the blood. Two months later, his headaches disappeared. The head doctor said:” We are not against headbanging. The risk of injury is very, very low. If our patient _____ (go) to a classical concert, this would not have happened.” He said heavy metal fans should carry on dancing, ____(say):“ Rock’n’roll will never die. Heavy metal fans should rock on.”