This impervious layer or boundary will retard the free diffusion of moisture. This condition is referred to as case hardening.

这一不透气的壳层(或边界层)会阻滞水分自由扩散，这种情形称为表面硬化。

youdao

Leave plant stems free to catch air and moisture and resist disease.

让植物自由的生长，接触空气和水分，抵抗疾病。

youdao

Today's modern, frost-free refrigerators work to draw the moisture out of the air, and consequently also out of the food.

今天现代的无霜冰箱能吸走空气中的水分，结果同样也会吸收食物中的水分。

youdao

But its fortifying magic works wonders to combat moisture-free air and hat head.

WSJ: Maintaining the Gloss | Outer Beauty