这个纸板衬背就是一个助力器。

The cardboard backing was just a strengthener.

youdao

纸箱内都衬有塑料布，是防水的，而且由于箱子是硬纸板的，所以在搬运的时候就会小心处理。

The cartons lined with plastic sheets are waterproof, and as the boxes are made of cardboard, they will be handled with care.

youdao

那个没必要担心。纸箱内都衬有塑料布，是防水的，而且由于箱子是硬纸板的，所以在搬运的时候就会小心处理。

No need to worry about that. The cartons lined with plastic sheets are waterproof, and as the boxes are made of cardboard, they will be handled with care.

youdao