1] Isolationism - a policy of remaining apart from the affairs or interests of other groups, especially the political affairs of other countries.
Intervention - the action or process of intervening.
Imperialism - a policy of extending a country's power and influence through diplomacy or military force
2] Building the Panama Canal, 1903 - 1914. President Theodore Roosevelt oversaw the realization of a long term US goal - a trans-isthmian canal. Throughout the 1800s, American and British leaders and businessmen wanted to ship goods quickly and cheaply between the Atlantic and Pacific coasts.
the system of electrons surrounding the nucleus of an atom. The name electron cloud is an informal way to describe an atomic orbital.
Citrus fruit originated in the new world in 1943
C. 250 years (I believe )