The word horsepower was first used two hundred years ago. James Watt had made the world' s first
1 used steam engine. He had no way of telling people
2 how powerful it was, for at that time there were no units for measuring power. Watt decided to
3 how much work one
4 horse could do in one minute. He called that unit one horsepower. With this unit he could measure the work his steam engine could do. He
5 that a horse could lift a 3,300-pound weight 10 feet into the air in one minute. His engine could lift a 3,300-pound weight 100 feet in one minute. Because his engine did ten times as much work as the horse, Watt called it a ten horsepower engine.
【正确答案】
1、widely, 2、exactly, 3、find out, 4、strong, 5、discovered
【答案解析】解析:discover意为“发现”,作谓语。