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

Q: Sexually do invertebrates reproduce.

A: How do invertebrates reproduce?
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Q: Mucous does the esophagus produce for lubrication.

A: What does the esophagus produce for lubrication?
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Q: Collision frequency is greater for homogeneous category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'.

A:
Collision frequency is greater for what category of catalysts, which also tend to be more sensitive to temperature and more 'expensive'?
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