B, barrier type protective effect when the cold sprayed zinc coating is oxidation, will produce a layer of zinc salt in the coating surface to provide barrier protection.
屏障式保护作用当冷喷锌涂料被氧化时，会在涂料表面产生一层锌盐层来提供屏障保护。
3
International trade implies an exchange between an origin (a) and a destination (b) subject to a trade barrier.