26码内长约16.2cm,27码内长约16.8cm,28码内长约17.4cm,29码内长约18cm,30码内长约18.6cm,31码内长约19.3cm,32码内长约20cm,33码内长约20.7cm,34码内长约21.3cm,35码内长约22cm,36码内长约22.6cm