high-quality grey iron

例句：

1. 1.This high-quality grey iron is used for building bridges and houses.
   这种高质量灰色铁被用于建造桥梁和房屋。
2. 2. The manufacturer claims that the high-quality grey iron has excellent wear resistance.
   制造商声称这种高质量灰色铁具有极好的耐磨性。
3. 3. The construction of this high-quality grey iron bridge will take several months.
   这座高质量灰色铁桥的建设将需要几个月时间。