The foundation on which many factories were built was the use of rich raw materials in local places.A. 许多工厂都是建立在使用当地丰富的原材料的基础上的。B. 许多工厂是用当地丰富的原材料打桩建造的。C. 许多工厂都是根据当地丰富的原材料的使用而建立的。