When did the u. s enter world war 1?

Which statement best describes why article 3 of the constitution gives congress the ability to create lower courts inferior to the supreme court from time to time

Prior to the presence of europeans on the continent, the slave trade in africa a) did not exist in any form. b) was limited to internal trade only. c) included the trans-saharan and indian ocean slave trade. d) was rarely needed due to the lack of an agricultural economy.

4. any area in which one nation has power over another; i.e. - this happened to china when it was defeated by japan