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

Input: Consider Input: Passage: Glutathione is a low-molecular-weight compound found in living cells that is produced naturally by the liver. Healthcare providers give glutathione intravenously to prevent side effects of chemotherapy and to prevent kidney problems. Answer: liver

Output: Glutathione is a low-molecular-weight compound found in living cells that is produced naturally by what?

Input: Consider Input: Passage: As you would expect, where plates collide there are lots of intense earthquakes and volcanic eruptions. The subducting oceanic plate melts as it reenters the mantle. The magma rises and erupts. This creates a volcanic mountain range near the coast of the continent. This range is called a continental arc . The Andes Mountains, along the western edge of South America, are a volcanic arc ( Figure below ). Answer: melts

Output: The subducting oceanic plate does what as it reenters the mantle?

Input: Consider Input: Passage: The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound . Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound . Ultrasound is too high-pitched for humans to hear. Answer: hertz
Output: The frequency of sound waves is measured in what unit?