1839 - William Otis receives a patent for the steam shovel.

1839年的今天，威廉·奥蒂斯收到了蒸汽铲的专利权。

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1839 - William Otis receives a patent for the steam shovel.

1839年的今天，威廉·奥蒂斯收到了蒸汽铲的专利权。

youdao