The researchers say they can find no indication that television has harmful physical effects on children.研究人员说他们没找到任何迹象说明电视有害于儿童的身体健康。I can't get it through to him that smoking is bad for his health.我没法说服他接受吸烟有害于健康的道理。It is unhealthy to do without sleep.不睡觉有害于健康。