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

Opaque is the term for matter that does not let any light pass through.
What is the term for matter that does not let any light pass through?

Water and humidity is the critical factor for the survival of segmented worms.
What is the critical factor for the survival of segmented worms?

Kingdom is the broadest category in the linnaean system.

What is the broadest category in the linnaean system?