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

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

Oxygen is transferred through capillaries.
Which blood vessels is oxygen transferred through?

Jellyfish type of animal in the sea spend most of their lives as medusae.

What type of animal in the sea spend most of their lives as medusae?