其部分原因是涡轮螺旋桨飞机结构坚固，部分原因是“空中拖拉机”公司生产的油箱有多层橡胶密封，一旦子弹射穿油箱，橡胶层就会自动封闭住弹孔，减缓燃油的渗漏。
In part this is because of the turboprops' robust design, and in part because Air Tractor's fuel tanks have rubber membranes which close around bullet holes to slow leaks.
多种封闭或密封防喷装置的方案也在构思之中。
A variety of schemes to either block up or seal off the blowout preventer are in development.
热缩塑料包是一个流程，在产品周围附上一个封闭的塑料包，通常使用密封胶密封，然后对产品加热，通常使用加热管道，收缩塑料膜使之附着在产品上。
Shrink-wrapping is a process where a closed bag is formed around the product, typically using a
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