EARTHLINGS MEET VENUS Which statement best expresses the central idea of the text?

Which sentence from a student's reflective essay contains a subject and verb error and needs to be edited? a. in my opinion, some of the voters seemed to need more information about their candidates. b. the documentary showed that dollars are often used instead of rubles in russia. c. the research shows that jackets made of wool are warmer than those made of cotton. d. in my opinion, either the doctors or the chief administrator need to make a quick decision.

The missionaries who appear in the novel are colonists from britain portugal spain italy

What point is the author trying to make by comparing the travel times of the first transcontinental railroad and the first transcontinental flight?