context: Concrete or concrete is a substance consisting of cement, sand, and water with the addition of a type of aggregate, such as a tooth or a brick,. Concrete is one of the most important building materials in the modern era, especially with its reinforcement with iron to become reinforced concrete. [1]
question: What is concrete?
answers.text: substance consisting of cement, sand, and water with the addition of a type of aggregate, such as a tooth or a brick,