二价钴的

例句：

1. 1. This alloy is made from a combination of iron and cobalt.
   这种合金是由铁和钴混合制成的。
2. 2. The cobalt in the alloy has a significant impact on its properties.
   合金中的钴对它的物理性质有显著影响。
3. 3. Cobalt is often used as an additive in paints to improve their durability.
   钴常被用作油漆的添加剂，以增强其耐用性。