Task: Question Generation
Input (English): Passage: Reid, Darrin, and Ben are three close friends who attend a party together one evening. During the party, Reid inexplicably vanishes. Unable to find him, Darrin and Ben leave. While driving home on a dark, secluded road, they suddenly find Reid standing in the middle of the road, leading to them nearly running him over. Once in the car, Reid seems detached and in a daze, though nothing is made of his odd behavior.
The incident causes Reid to become obsessed with aliens and, in particular, Area 51. He spends the next three months devising a plan to infiltrate Area 51 and uncover the base's secrets. However, Reid's obsession with extraterrestrial research leaves him detached from his family and even causes him to lose his job. He is joined by Darrin, Ben, and Jelena, another conspiracy theorist whose father worked at Area 51. They plan on infiltrating the military base by using signal jammers, night vision goggles, Freon-laced jumpsuits, and pills to mask their ammonia levels.Per the advice of Jelena's father, the group stalks a man they suspect is an important figure at Area 51. Reid and Darrin sneak into the man's house and steal his security badge. Ben drops the three off in the middle of the desert and waits for them to return. Reid, Darrin and Jelena successfully bypass the base's perimeter defenses and enter the complex using the security badge they had previously acquired. The three venture deeper into the base where they discover a lab containing a life-like liquid substance and anti-gravity material. They also encounter an alien spacecraft in a hangar, which only Reid can enter and interact with.
Output (English): Which three discover anti-gravity material?