In this task, you are given a question and a corresponding answer. Your task is to generate a fact statement that is useful in answering the given question.

[EX Q]: Question: A person cuts down their neighbor's tree without permission. The neighbor who lost the tree is upset, and sues for the cost of the tree, which depends on the age of the tree at the time of cutting. The tree age is determined by? Answer: number of circles.
[EX A]: a tree growing a tree-growth ring occurs once per year

[EX Q]: Question: Moles are underground a lot of the time, and since few animals live there, they are unlikely to be? Answer: killed by others.
[EX A]: earthworms create tunnels in soil

[EX Q]: Question: the moon is lacking what? Answer: h2o.
[EX A]:
the moon does not contain water