Who said the u. s. recognition of china bridged "the vastest ocean in the world"?

In the mid-1800s, native americans who had lived in the westtraded their manufactured goods with settlers. were able to resist diseases carried by settlers. offered their services as guides to settlers. prevented settlers from moving onto their territory.

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.

What are contributions made by rene descartes