One afternoon in January in 1998, Susan Sharp, 43, and her 8-year-old son David, were walking across an icy square, when Susan's cane(手杖) slipped on the ice. Her face first into the mud. David her mother's side, “Are you all right, Mom？” , Susan pulled herself up, “I'm okay, Honey,” she said. Susan was falling more since she had trouble walking. Every inch of ice was a 40 danger for her. “I wish I could do something,” the boy thought. David, too, was having of his own. The boy had a speech problem, so at school he talked . One day, David's teacher announced a homework. 'Each of you is going to come up with an ,' she said. This was for 'INVENT AMERICA', a national competition to encourage creativity in children. An idea David one evening. If only his mother's cane didn't slip on the ice. “What if I your cane to a nail coming out of the bottom” he asked his mother. “ the sharp end would scratch(划破) floors,” Susan said. “No, Mom, I make it like a ball-point pen. You take your hand off the button and the returns back up.” Hours later the cane was finished. David and his father as Susan used it to walk 50 feet above the . Happily Susan cried out, “It !” In July 1999, David was national winner for the 'INVENT AMERICA'. David began to make public appearance. Thus he was forced to communicate .Today, David is nearly free of his speech problem, and his is becoming well accepted. 小题1: A．dropped B．touched C．lay D．fell 小题2: A．rushed to B．stood by C．looked at D．ran around 小题3: A．Firmly B．Easily C．Shakily D．Quickly 小题4: A．frequently B．slowly C．freely D．heavily 小题5: A．hiding B．possible C．certainly D．waiting 小题6: A．method B．trouble C．disease D．hope 小题7: A．little B．few C．much D．more 小题8: A．useful B．strange C．special D．common 小题9: A．invention B．appearance C．experience D．experiment 小题10: A．reminded B．encouraged C．hit D．occurred 小题11: A．fastened B．fixed C．stuck D．tied 小题12: A．So B．And C．But D．For 小题13: A．would B．might C．did D．need 小题14: A．pen B．hand C．nail D．cane 小题15: A．helped B．supported C．noticed D．watched 小题16: A．ice B．street C．yard D．square 小题17: A．helps B．operates C．succeeds D．works 小题18: A．praised B．received C．won D．declared 小题19: A．more slowly B．more clearly C．more carefully D．faster 小题20: A．cane B．speech C．mother D．story