Cleopatra was involved with caesar
United States involvement in the Boxer Rebellion would have contradicted the ideals George Washington laid out in his farewell address. It also would have violated the Monroe Doctrine by becoming involved in Europe's subject matters.
I think the first one is Royal Society. and the other one is I think France.
Opportunity cost is what must be given up in order to gain something else. Opportunity cost forces consumers and producers to make choices.