C245 Research bottleneck

After that, Shi Fu added in some more water. When the water came in contact with the mixture of sand and powder, it was quickly absorbed.

As Shi Fu stirred the mixture evenly, the mixture in the wooden box was crumpled into a ball and its color turned black grey.

When Zhao Fengnian saw this, he was surprised. He felt that this was no different from the cement he had seen in his previous life