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

Simple kind of diffusion do small hydrophobic molecules squeeze through lipid molecules.
What kind of diffusion do small hydrophobic molecules squeeze through lipid molecules?

Wave amplitude and wavelength are two important measures of wave size.
Wave amplitude and wavelength are two important measures of what?

Trash can kingdom is the protist kingdom sometimes called as.
What is the protist kingdom sometimes called as?