The vacuum flask has a strong casing, which won't crack or chip.这种热水瓶瓶身坚固，不易断裂破碎。This wire has a plastic casing.这种电线外包塑料.There is a window fitting in a casing.有一扇装在框内的窗....
The casing was driven into the soft muds in the top.套管被送入软岩粉顶.The conventional casing centralizer can not meet the requirements of expandable casing.传统的套管扶正器满足不了可膨胀套管的扶正要求.We need large quantity of natural casing waste f...