| 摘要 |
<p>Flexible tubular rings of plastic, aluminim or other material are set in rows on the inflated balloon widest where the balloon's diameter is greatest. Alternatively a flexible tube of similar material is spirally wound round it from bottom to top, with sections simultaneously tiered and individual tube layers interconnected. The gas is then let out and the balloon is removed from inside. An inner or outer lining is pref. subsequently provided and provision is also made for doors and windows when appropriate.</p> |
