兰桑戴克编辑《萨克罗博斯科的天球及其评论》 。芝加哥：芝加哥大学出版社， 1949年。页118 - 23 。
Thorndike, lynn, ed. the sphere of sacrobosco and its commentators. chicago : university of chicago press, 1949. pp. 118 - 23
去年获胜的美国数学奥林匹克代表队的总教练罗博深说：“挑战在于，如果某些类型的人正在做某事，其他人就很难成功打入其中。”
"The challenge is if certain types of people are doing something, it's difficult for other people to break into it," said Po-Shen Loh, the head coach of last year's winning U.S. Math Olympiad team.
今年5月，罗琳开始撰写名为《伊克博格》的新故事，它可以在网上免费阅读，以帮助娱乐那些因新冠肺炎疫情而待在家里的人。
In May, Rowling started writing a new story called The Ickabog, which was free to read online to help amuse people who stayed at home because of COVID-19.
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