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交通运输:操纵空气
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The safe descent of the three animals, which has already been related, showed the way for man to venture up in a balloon. In our time we marvel at the daring of modern airmen, who ascend to giddy heights, and, as it were, engage in mortal combat with the demons of the air. But, courageous though these deeds are, they are not more so than those of the pioneers of ballooning.
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