未分类题

One afternoon in January 1989, Susan Sharp, 43, and her 8-year-old son, David, were walking hard【C1】______an icy parking lot,【C2】______Susan's cane slid on the ice. She【C3】______face first into the mud. David【C4】______to his mother's side.
'Are you all right, Mom?'
【C5】______, Susan pulled herself up. 'I'm okay, honey, 'she said.
It had been nearly two years since Susan had trouble walking. She was falling more【C6】______now. Every inch of ice was a【C7】______danger for her. 'I wish I could do【C8】______,' the boy thought. '
David, too, was having【C9】______of his own. The boy had a speech defect. At school he【C10】______asked questions or read aloud.
One day David's teacher announced a【C11】______assignment. 'Each of you is going to come up with an invention,' she said. This was for' INVENT AMERICA!', a national competition to encourage creativity in【C12】______
An idea hit David one evening.【C13】______only his mother's cane didn't slip on the ice, he thought. 'That's it ! 'David realized.
'What if I fixed your cane so a nail stretched out of the bottom?' he asked his mother.
'【C14】______the sharp end would scratch floors,' Susan said.
'No, Mom. I could make it like a hall-point pen. You take your hand【C15】______the button and the nail returns back up. 'Hours later the cane was finished. David and his father, Jeff,【C16】______as Susan used it to walk 50 feet across the【C17】______'It works!' she said.
In July 1989, David was declared national winner at the annual 'INVENT AMERICA!' ceremony in Washington D. C.
As David began to make【C18】______appearances, he was forced to communicate more closely. Today, David is nearly【C19】______of his speech defect, and his cane is waiting to be widely used.【C20】______the boy who once people had trouble talking now hopes to start making canes for people who have trouble walking.
【C1】
A．at
B．in
C．over
D．across