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

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


Question: Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as embryos.

Answer: Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as what?


Question: The skin are pressure receptors mainly found.

Answer:
Where are pressure receptors mainly found?