carbon constructional steel round

例句：

1. 1.This type of steel is commonly used inconstruction for its strength and durability.
   这种钢材因其强度和耐用性而常用于建筑。
2. 2.The engineer designed the building with a focuson energy efficiency, using carbon steel constructional steel round as an essential material.
   工程师在设计建筑时，特别注重能源效率，使用碳钢建筑用圆管作为关键材料。
3. 3. The construction company chose thistype of steel because it was cost-effective and could be easily shaped into variousshapes.
   该建筑公司选择这种钢材是因为其成本效益高，且易于加工成各种形状。