WHEN local amputee (截肢患者) Stephen Cornell noticed a robbery (抢劫) in progress at a neighborhood convenience store in Middleton, Massachusetts, he took action. He considered fighting the thief directly, but had second thoughts. Cornell simply used his prosthetic leg (假肢) to trip the escaping robber. The stumble (绊倒) allowed the owner of the store to control the robber until police could arrive. The suspect’s (嫌疑犯) plan had been running smoothly (顺利地) but now thanks to Cornell, his court costs, fines and punishment will probably cost him an arm and a leg.