Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table below . Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. Answer: renewable resources

Ex Output:
What are natural resources which can be replaced in a relatively short period called?

Ex Input:
Passage: Carbon moves through ecosystems in two cycles that overlap. In the biotic cycle, it moves between living things and the air. In the abiotic cycle, it moves between the air, ground, and oceans. By burning fossil fuels, humans have increased the amount of carbon dioxide in the air. Answer: biotic cycle

Ex Output:
In what part of the carbon cycle does carbon move between living things and the air?

Ex Input:
Passage: Muscle contraction occurs when muscle fibers get shorter. Literally, the muscle fibers get smaller in size. To understand how this happens, you need to know more about the structure of muscle fibers. Answer: muscle contraction

Ex Output:
What occurs when muscle fibers get shorter?