凸轮是自动化机械的关键零件之一，由于形状复杂、加工要求高，是机械制造领域里较难加工的零件。

Cams are one of key parts of automatic machines, but cams are difficult machined parts for their complex shape and higher machining requirements.

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所以周六一大早，在气温比华氏零度（约零下18摄氏度）高不了多少的天气里，为获得见证这段历史结束的免费门票的机会，几千人在外面等待着。

And so early Saturday, in temperatures barely above zero, thousands waited outside for the chance to receive free tickets to witness the end of that story.

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