Write a fact related to the given fact, based on the given topic word. Note that, your fact should have at least one word in common with the given fact. All facts in this task refer to scientific facts. Your related fact must form a chain with the given fact. Chains form when two facts connect together to produce the third fact. An example of a chain is: "pesticides cause pollution" (given fact) + "pollution can harm animals" (related fact) → "pesticides can harm animals" (connected chain). Avoid creating simple paraphrases of the given fact. While your generated fact should be related to the input fact, they must describe slightly different scientific phenomena. It's okay if your related fact includes some irrelevant information, provided that it has some overlap with the given fact and it contains some words corresponding to the provided topic.
--------
Question: Fact: a fire requires oxygen to burn. 
Topic: moon oxygen.

Answer: There is no "gaseous" oxygen on the Moon and the Moon itself is bone dry.


Question: Fact: when the season changes , the amount of daylight will change. 
Topic: daylight changes.

Answer: Changing weather effects and daylight times.


Question: Fact: a valley is formed by a river flowing. 
Topic: flowing river erosion.

Answer:
Fast flowing rivers tend to pick up more pebbles, sand and other materials that cause erosion.