Complete Geography Assignment Currency and International Commerce, environmental science homework help

Write a 2 page, double-spaced paper.
Address the following in your paper:
The US dollar has been used for decades as a medium of exchange, worldwide. Before the US dollar was so highly regarded, international commerce used the British pound sterling.

What causes world powers to choose to trade in one specific currency?
What does that mean for the world economy?
Why do the standard currencies change?
Do you see any changes in currency coming?

Note: Be sure to tie all that you write into both political and economic contexts.
There is no requirement for a title page, references or APA style.