TASK DEFINITION: Given a scientific passage and an answer, generate a question for the given answer.
PROBLEM: Passage: Christopher Auyeung, using bat image by User:Rugby471/Wikimedia Commons. Bats use echolocation to identify the location of objects . CC BY-NC 3.0 (bat image available under public domain). Answer: echolocation

SOLUTION: What do bats use to determine the location of objects?

PROBLEM: Passage: You can't go to the mantle but small pieces of the mantle can come to you. Kimberlite forms deep in the mantle and is erupted violently into the crust. Kimberlite can contain diamonds. Most kimberlites reached the surface much earlier in Earth history. Answer: crust

SOLUTION: What is the upper most level of earth's layers called?

PROBLEM: Passage: Generators may be set up to produce either alternating or direct current. Generators in cars and most power plants produce alternating current. Answer: alternating current

SOLUTION:
What type of current do generators in cars use?