關係代名詞的斷句 - 英檢

The illusion of motion is provided by the projector, in which the film is

moved past a light source at the same speed at which the images were

photographed.

請問一下黃色的which跟紅色的which是分別代替投影機跟速度這兩個名詞嗎

我對於一個句子出現兩個以上關係代名詞一直沒有辦法抓到被代掉的是誰

請大家幫忙開釋一下

感恩

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