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

Q: Lipids are available to the body from three sources.

A: Lipids are available to the body from how many sources?
****
Q: Lichens are not a single organism, but rather an example of a mutualism.

A: Lichens are not a single organism, but rather an example of a what?
****
Q: Mucous does the esophagus produce for lubrication.

A:
What does the esophagus produce for lubrication?
****