In this task, you are given a fact statement and question based on the fact. Your task is to generate the correct answer for the question. The answer needs to be generated using the context fact statement.
--------
Question: Fact: a cactus stem is used for storing water. Question: Someone stranded in the Sahara can potentially save their life with a?

Answer: prickly plant's trunk


Question: Fact: rocks often contain large amounts of metal. Question: rocks often contain large amounts of?

Answer: aluminium


Question: Fact: the lunar surface contains many craters. Question: The biggest things on the moon are?

Answer:
craters