Stream of consciousness: To answer this question, we should know that: He ruled Morocco from 1912 until his death in 1927.
Q: Context: Yusef ben Hassan (1882 -- November 17, 1927) (Arabic: السلطان يوسف بن الحسن ‎) was a Sultan of the Alaouite dynasty. He ruled Morocco from 1912 until his death in 1927.

Question: who was the ruler of morocco between 1912 and 1927?
A: Yusef ben Hassan

Stream of consciousness: To answer the above question, the relevant sentence is: It was first recorded by The Four Voices in 1960 and released as a single, but their recording was not a hit.
Q: Passage: "Sealed with a Kiss" is a song written by Peter Udell and Gary Geld. It was first recorded by The Four Voices in 1960 and released as a single, but their recording was not a hit.

Question: Based on this passage, who sings the song sealed with a kiss?
A: The Four Voices

Stream of consciousness: The relevant information to answer the above question is: NASA's Mars Exploration Rover (MER) mission is an ongoing robotic space mission involving two Mars rovers, Spirit and Opportunity, exploring the planet Mars.

Q: NASA's Mars Exploration Rover (MER) mission is an ongoing robotic space mission involving two Mars rovers, Spirit and Opportunity, exploring the planet Mars. It began in 2003 with the launch of the two rovers: MER-A Spirit and MER-B Opportunity -- to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A Spirit was active until 2010, while MER-B Opportunity is still active in 2018, and holds the record for the longest distance driven by any off-Earth wheeled vehicle.

Based on this passage, what are the names of the two rovers currently exploring mars?
A: Spirit