perforations是什么意思？

perforations

例句

• Tear off the form along the perforations and send it to Sales... 沿着纸孔撕下表格，寄给销售部。
• In addition, chronic tympanitis, perforations, swimming is also easy to make water. 此外, 患有慢性中耳炎 、 鼓膜穿孔的人, 下水游泳也容易使炎症加重.
• The dangerous type chronic otitis media occurs with pars flaccida and marginal perforations. 慢性中耳炎的危险型可出现鼓膜松弛部的穿孔和鼓膜边缘性穿孔.
• Tear the sheet of stamps along the perforations. 沿齿孔把邮票撕开。
• When held to the light the small oblong leaves are seen to possess tiny perforations. 迎着光看时，就会发现椭圆形小叶子上有微小的孔眼。