Explanation:
I think C is more reasonable than the others, but I'm not sure. Correct me if I'm wrong.
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.
He’s trying to say that it would be almost impossible to continue their journey without having an important part of his mind outwards and shared with the world
C. North America. 'the french and indian war' is however more of an american name for the war, the europeans mostly call it the 'seven years war'
