3d印制技术对物流公司的生意构成的威胁显而易见：如果企业可以在任何需要的地方印制急需部件，为什么它还选择空运呢？
The threat to the logistics firm's business is clear: why would a company airfreight an urgently needed spare part from abroad when it could print one where it is required?
日晷的主要部件是由一根晷针和刻有刻线的晷面组成，随着太阳在天空运行，晷针的投影像钟表指针一样在晷面上移动，就可以指示时辰。
The main parts of a sundial are an erect stylus and a calibrated disk. As the sun moves in the sky, the shadow of the stylus moves like a clock hand around the disk indicating the hours.
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