The correct answer for the question that is being presented above is this one: "B. building of the transcontinental railroad --> disappearance of the frontier." The pair of events that did the first event most directly influence the second is the building of the transcontinental railroad --> disappearance of the frontier.
Measurement is the assignment of a number to a characteristic of an object or event, which can be compared with other objects or events.
Nope.......................
