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日晷
Churchyards often have sundials in them. 教堂大院里通常设置日晷。
Inventors created sundials, which indicate time by the length or direction of the sun's shadow, to track temporal hours during the day. 当时的发明家制造了日晷，利用太阳阴影的长度或角度，来测量白天真时的变化。
