题目：The diagrams below show the stages and equipment used in the cement-making process, and how cement is used to produce concrete for building purposes.
The process given by the flow charts is about the detailed steps and facilities which are utilized in the production of cement and concrete.
As for the first chart, cement production involves the following certain steps. At first, limestone and clay are set into a crusher, by which they become powder. After being mixed, the powder is transmitted into the next rotating process and it will be heated. Next, the mixture goes into a grinder where the cement comes out. Finally, the cement can be packed in bags.
In terms of concrete production, in the first step, 25% sand and 50% small stones are put together, with a combination of 15% cement and 10% water. In the next stage, the mixture can be poured into a concrete mixer. Finally, the production of concrete is successfully completed.
All in all, it is clear to see that compared with the production of cement, that of concrete is rather simple.