Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Producing sperm and secreting testosterone are the main functions of male reproductive system system.

Answer: Producing sperm and secreting testosterone are the main functions of what system?


Question: Respiratory acidosis is considered to be problematic because excess co2 in blood.

Answer: Why is respiratory acidosis considered to be problematic?


Question: Three ways that waves may interact with matter are reflection, refraction, and diffraction.

Answer:
Three ways that waves may interact with matter are reflection, refraction, and what?