Definition: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Old Faithful is the best-known geyser in the world. You can see a picture of it in Figure below . The geyser erupts faithfully every 90 minutes, day after day. During each eruption, it may release as much as 30,000 liters of water!. Answer: old faithful
Output:
What is the best-known geyser in the world that also faithfully erupts every 90 minutes?