阅读下面短文，在空白的地方填入适当的内容（不多于三个单词）或括号内单词的正形式
It was the ambition of an eleven year old boy in Kansas City to be an engine-driver. Born without arms, he had been sent to special schools      he learned to use his     (foot) as “ hands”. He spent all his spare time     (watch) trains and one day his dream came     (true). Seeing a deserted engine , the boy climbed in, he had no      (difficult) in starting it up with his feet . Soon he was traveling along  forty miles an hour. Signalmen could not see the young driver, so they set out   (stop) the train. Meanwhile the boy reached Missouri, stopped the engine himself, and then made it    (go) backwards. When he was near home, a railway-man caught up with the engine and stopped it. At first, he was very angry, but he smiled     the boy said simply, “I like trains.” “Well, I’m glad you don’t like planes!” answered    railway-man.