Before the 1800s, builders used cast iron. But they found that structural steel beams set in concrete allowed them to frame tall buildings that were more fire resistant and more structurally sound than cast iron. Since that time, steel has not only become the best building material for commercial construction but closely tied to economic health.
I don't understand the question fully please explain?
Hi honey I have the mail I sent to the email to you have it in a minute you have a chance to call the number in a while or if it gets you in it you have to a couple minutes late I have to pick you off I
