基本解释齿孔同根派生 perforations相关词英汉例句Tear the sheet of stamps along the perforations.沿齿孔把邮票撕开。Grooves extend to the finished edge, but rear perforations are not visible.凹槽延伸到成品的优势，但后排齿孔中不可见。perforations更多例句