Complex sentence: They released their debut single "Function" in 1997, and followed it up in 1998 with their debut album, "Wormhole" which has been described as the greatest drum and bass album of all time.
Split into simpler sentences: They released their debut single "Function" in 1997. The following year they released their debut album, "Wormhole" which has been described as the greatest drum and bass album of all time.