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

Input: Consider Input: Passage: Wavelength is one way of measuring the size of waves. It is the distance between two corresponding points on adjacent waves, and it is usually measured in meters. How it is measured is a little different for transverse and longitudinal waves. Answer: waves

Output: What do wavelengths measure the size of?

Input: Consider Input: Passage: With the naked eye, bacteria just look like a slimy smear on a petri dish. How can we study them in more detail? The invention of the microscope has allowed us to see bacteria, cells, and other things too small to be seen with the naked eye. Answer: slimy smear

Output: How does the bacteria look when seen with the naked eye?

Input: Consider Input: Passage: Elemental bromine gas can be generated by reacting sodium bromide with elemental chlorine. The other product is sodium chloride. Write a balanced chemical equation for this reaction. Saylor URL: http://www. saylor. org/books. Answer: elemental bromine gas
Output: What gas can be generated by reacting sodium bromide with elemental chlorine?