BBC地平线：网络攻击-国家医疗服务系统瘫痪之日

     A few weeks ago, the National Health Service was hit by a widespread and devastating cyber attack - Horizon tells the inside story of one of the most challenging days in the history of the NHS       　　On the morning of 12 May the attack started       Appointment systems, pathology labs, x-rays and even CT scanners were infected - putting not just data but patients lives at risk, and on eve