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.

Fact: sand dunes are made of sand. Question: The mounds at the beach are made of?
silica

Fact: a cactus stem is used for storing water. Question: Someone stranded in the Sahara can potentially save their life with a?
prickly plant's trunk

Fact: Earth is made of rock. Question: Ground has?

elements