First, USA and Canada are very different. You can tell after living in North America for a long while. Just like France and Germany, they are different but Chinese may not be able to tell.
Second is about 超级大国. USA is now the only super power in the world because they spend too much on military. Smallyam is very right. Canada always wants to remain as a neutral country, though this is not the fact any more.
In terms of natural environment, come on, they are very different. Do you know Canada as the biggest oil reserve in the world? After Middle East finishes their oil in 25 years, Russia and Canada will continue to provide the world with natural gas and oil.