2014年全国大学生英语竞赛a类初赛试题及详解_精品.ppt

For example: One of my favorite writers are Charlotte Bronte. She was born in the early nineteenth century when women had far fewer opportunities ∧ they have now. She lived in a small village in Yorkshire and she took great pleasure in walking on the moors where near her home. __is__ than _ √_ where 　 Perhaps one of the best-known accidental discovery is Sir Alexander Flemings discovery of penicillin. In 1922 Fleming accidentally discovered an antibiotic that killed bacteria but not white blood cells .While suffering from a cold, Fleming made a culture from some of his own nasal secretions. As he examined the culture dish, filling with yellow bacteria, a tear fell from his eye into the dish. The next day when he examined the culture, he found a clear space which the tear had fallen. His keen observation and inquisitiveness led 82._____ 83._____ 84._____ 85._____ him to the correct conclusion: the tear contained a substance that caused rapid destruction of the bacteria, but was harmless to human tissue. The antibiotic in the tear he named lysozyme. It turned to be of little practical importance, because the germs that lysozyme killed were relatively harmless, and this discovery was an essential prelude to this of penicillin, as we shall see. In 1928, Fleming was doing a research on influenza. While carrying out some routine laboratory work that involved microscopic examination of cultures of 86._____ 87._____ 88._____ 89._____ bacteria growth in petri dishes (flat glass dishes with covers), Fleming notice in one dish an unusual clear area. Examination showed that the clear area surrounded a spot where a bit of mould had fallen onto the dish, which had been left uncovered. Remembering his experience with Iysozyme, Fleming concluded that the mould was producing something that was dead to the Staphylococcus bacteria in the culture dish. Fleming isolated the mould and identified it as belonging to the genus Peni