Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: Through tubular ducts part do exocrine glands discharge their contents.

Output: Through what part do exocrine glands discharge their contents?


Input: Consider Input: Diffraction is the phenomenon in which light and sound waves become circular at the point source of a barrier.

Output: What is the phenomenon in which light and sound waves become circular at the point source of a barrier?


Input: Consider Input: Narrow air passages make breathing difficult due to respiratory system disease.


Output: What makes breathing difficult due to respiratory system disease?