TASK DEFINITION: Turn the given fact into a question by a simple rearrangement of words. This typically involves replacing some part of the given fact with a WH word. For example, replacing the subject of the provided fact with the word "what" can form a valid question. Don't be creative! You just need to rearrange the words to turn the fact into a question - easy! Don't just randomly remove a word from the given fact to form a question. Remember that your question must evaluate scientific understanding. Pick a word or a phrase in the given fact to be the correct answer, then make the rest of the question. You can also form a question without any WH words. For example, "A radio converts electricity into?"
PROBLEM: Fact: some fleas and ticks live on the surface of their host.

SOLUTION: what sometimes lives on the surface of their host?

PROBLEM: Fact: Some species of snakes can go several weeks between meals.

SOLUTION: Several species of what can go several weeks between meals?

PROBLEM: Fact: Growth of an area can be determined by the average number of people per unit of area.

SOLUTION:
What can be determined by the average number of people per one unit of area?