I think steel Because it is versatile Building material
Cast iron!
iron it holds more weight(300 strength) and its not to dense(7.90).
To make it stronger or maybe too nicer
metal(steel), bricks, concrete
The current London Bridge is a pre-stressed concrete box girder bridge.
A toothpick bridge, if you make it just right. :)
over a period of time it will make the metal expand and will collapse if it is a bridge or something
It may be potassium or ammonium ions And chloride or nitrite ions that have similar mobility in solution
triangleANS 2 - There is no 'best shape' - each bridge is designed for a particular place and can be almost any kind of construction.
it is the metal
plastic because if you use metal it would be heave and if you use wood it would brake and glass would be dangrous
Iron, supported on granite piers.
I doubt its the best, but it's interestingly resistant to corrosion.