precast concrete unit

例句：

1. 1. The construction of this precast concrete unit is completed in three days.
   这个预制混凝土构件的施工在三天内完成。
2. 2. The precast concrete unit was installed in the factory and then transported to the construction site.
   预制混凝土构件在工厂安装后被运输到施工现场。
3. 3. The precast concrete unit has a high strength and durability, which makes it widely used in various engineering projects.
   预制混凝土构件具有很高的强度和耐久性，因此广泛应用于各种工程项目中。