What innovation allowed henry ford to make cars available to americans for a lower cost? a. the use of assembly lines b. a drop in the price of oil c. cheaper steel for car frames d. the development of faster railroad deliveries

no statements but ok.

the statement that best describes the idea of manifest destiny that was used in the 19th century would be that "it was fate that the united states would continue to  expand westward," since people thought the us was "destined" to do so. 

the correct answer is b.