high silver crust

例句：

1. 1. The high silvercrust on the surface of the metal isa sign of its durability.
   金属表面的高银层是其耐用性的一个标志。
2. 2. Thehigh silver crust protects the metal fromcorrosion.
   高银层保护金属免受腐蚀。
3. 3. The high silver crust was formed duringthe metal's initial cooling process.
   高银层是在金属初始冷却过程中形成的。