However,he made a surprise appearance at the Democratic National Convention to support Barack Obama's candidacy for president.
VOA: special.2009.09.13
The mathematical theory of probability was unknown until that time and you can see that insurance suddenly made an appearance at that time.
在那之前,概率的数学理论,是不存在的,而随着概率论的出现,保险业也突然出现了
Benny made his first appearance on radio in Nineteen Thirty-Two.
VOA: special.2009.10.11
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