TASK DEFINITION: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
PROBLEM: Question: Which planet is closest to the sun? Answer: mercury

SOLUTION: Mercury is closest to the sun.

PROBLEM: Question: During an earthquake, wet soils become like what? Answer: quicksand

SOLUTION: During an earthquake, wet soils become like quicksand.

PROBLEM: Question: What celestial events are the source of elements heavier than iron? Answer: supernovas

SOLUTION:
Supernovas are the source of elements heavier than iron.