Hardens

The heat of the sun hardens clay.

Cement hardens in 2-3 hours.

The symbols of the body and spirit for humble people should be the tree and water respectively, since the tree hardens externally and matures over time in order to offer people in need refuge and have them shadowed; on the other hand water lies calmed in peace, is useful for everyone equally and moreover it has a devastating power capable of destroying the most powerful nations of the world.

Concrete hardens after it's poured.

Necessity even hardens the timid.

Cement hardens in two or three hours.

Cement hardens in two to three hours.

Lava hardens.

Steel hardens in one second.

The steel hardens in one second.