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.

Question: Which likely increased atmospheric CO2 recently? Answer: motorcycles.
carbon dioxide concentrations in the air have increased over the last decade dramatically

Question: Which of these could be a reason why the stars seem to be in a different place at dusk than at dawn? Answer: rotation of the earth.
the Earth rotating on its axis causes stars to appear to move across the sky at night

Question: In a forest without anyone around, a fire may be started by? Answer: electricty.

lightning can cause a forest fire