What was charles darwin's theory regarding plant and animal life

Even though both ww1 and ww2 were in many ways the same conflict with basically the same countries facing off against each other, the way each war started was significantly different. the question is how what were the differences on how they started

Why were presidents andrew jackson and martin van buren unwilling to annex texas? a. they did not want texas to be admitted to the union as a slave state. b. they feared that the annexation of texas as a slave state would lead to political problems within the union. c. they thought that texas was too large to be admitted to the union as one state. d. they did not believe in the idea of manifest destiny.

1. what potential advantages could companies like standard oil offer consumers?