We would ask you to be particularly careful to seal each box into a watertight bag before packing into cases.

在装入箱子之前，请特别小心地将每个盒子封入不漏水的袋子。

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To make(a boat) watertight by packing seams with a waterproof material, such as oakum or pitch.

麻纤维，有时涂上焦油、杂酚或沥青作保护层，主要用于木船上捻缝和填塞管子接头。

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