Interdependence in the Subway
The Subway is interdependent because we depend on other countries to give the U.S. materials for the building of our subways, and we give other countries materials that they need to build their subways. We depend on the successful designs from London so we can start off where they stopped instead of starting from scratch. We depend on the past so we can learn from our mistakes to evolve into a better subway. The final proof of interdependence in the subway is that there are many subways around the world. When one subway finds new technology, we all take that technology to upgrade our own subways. Each country depends on other countries for materials and tips for how to evolve their subway to make it more modern.