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

Diabetes is unpreventable in the type one form but may be prevented by diet if it is of the second type.
What disease is unpreventable in the type one form but may be prevented by diet if it is of the second type?

Lipids are available to the body from three sources.
Lipids are available to the body from how many sources?

Herbivores are heterotrophs that eat only or mainly plants.

Herbivores are heterotrophs that eat only or mainly what?