I'm pretty sure he only abdicated once. :)
Explanation:
The purpose of Hay's notes was to grant all the major powers equal access to Chinese trade and reduce the influence of countries that already had an especially large hold in China (such as Japan and Russia) so they couldn't force other countries (particularly the United States) out of the Chinese market.
The Roman Empire officially collapsed at 476 C.E.
Answer:
I say that the answer is C
~Hello there! ^_^
your question: Which official is the most powerful member of the White House..?
Your answer: The Chief of staff is the official that is the most powerful member of the White House. This person guides the White House staff.
~Hope this helps! :D