i According to the NASA astronaut Neil Armstrong, the aliens ________ a base onthe Moon.

The sentence should correctly read: "According to NASA astronaut Neil Armstrong, the aliens have built a base on the Moon."

Neil Armstrong, the first human to set foot on the Moon, did not make any claims about aliens or their presence on the Moon in his public statements. This statement seems to suggest a conspiracy theory or fictional narrative rather than a factual report. In reality, the exploration of the Moon has been a significant scientific endeavor, and there has been no credible evidence of extraterrestrial life or bases being established there. Armstrong's focus during his Moon landing was primarily on exploration and scientific research.