His name was Fleming, and he was a poor Scottish farmer. One day, he saved a   terrified boy from a black bog (沼泽) by accident.
The next day, a fancy carriage pulled up to the Scotsman’s sparse surroundings.  
____   elegantly- dressed nobleman stepped out and introduced himself      the father of the boy Farmer Fleming had saved.
“I want to repay you,” said the nobleman. “You saved       son’s life.”
“No, I can’t accept payment for what I did,” the Scottish farmer replied,    _____waving off the offer. At that moment, the farmer’s own son came to the door of the family hovel.
“Is that your son?” the nobleman asked. “Yes.” the farmer replied proudly．
“I’ll make you a deal. Let me take him and give him a good education.   ___  the boy is anything like his father, he will grow to be a man you can be proud of.”
And that he did. In time, Farmer Fleming’s son graduated   ____ St. Mary’s Hospital Medical School in London, and went on to become known throughout the world as the noted Sir Alexander Fleming, the discoverer of Penicillin (青霉素)．
Years afterward, the nobleman’s son was stricken   __   a serious disease. What saved him？Penicilllin.