Перепишите предложения, употребив прилагательные в скобках в сравнительной или превосходной степени, и переведите их.

1. Broken stone is (suitable) material for ballast.
2. The concrete sleepers are (reliable) than the wooden crossties, and they last (long).
3. (Deep) metro system in the world is built in St.Petersburg: some stations and tunnels lie as deep as 100-120 meters below the surface.