CASabbr.高级研究证书（=Certificate of Advanced Studyabbr.标定空速（=Calibrated Air Speed)Casinan.卡西纳(在意大利；东经 10º30' 北纬 44º31')

1. First, connect the guide shoe and the casing shoe.
   先接好引鞋和套管鞋。
2. Through study,the reason is off-centralizing casing.
   研究发现，套管不居中是该问题的原因所在。