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

Hookworms infest the intestines.
What part of the body do hookworms infest?

One of the properties of an air mass is that an air mass has similar temperature and moisture properties throughout it.
Which of the following is true regarding the properties of an air mass?

The outer core of the earth is molten.

Which layer of the earth is molten?