齿孔

齿孔

chǐ kǒng

{机} sprocket hole

{摄} perforations; film perforations

齿孔酸 eburicoic acid;

齿孔调制 sprocket-hole modulation

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齒孔|齿孔 [chǐ kǒng] ► perforations (on a postage stamp)