Why did one-half of the Moon's surface remain
hidden from human sight until the era of space
probes, which started in 1959?

The moon's revolution around its axis and the moon's revolution around the Earth take the same time, approximately 27 days. That causes one side of the Moon to always face the Earth while the other side always faces away from the Earth. That is why it took probes to go into space to photograph the side that is never visible from Earth for people to be able to see it.

all of the answers are correct.

falsification is manipulating research materials, equipment, or processes or changing or omitting data or results such that the research is not accurately represented in the research record. plagiarism is the appropriation of another person's ideas, processes, results, or words without giving appropriate credit.

explanation:

i really dont know but i will try okay.

so i think u would just add all them up and get your answer..