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: An example of playing a musical instrument is strumming a guitar string. Question: School children often play a musical instrument by?
sweeping thumb across elastic band over a beverage carton

Fact: An electrical conductor is a vehicle for the flow of electricity. Question: An electrical conductor is needed to?
bake a red velvet cake

Fact: an ecosystem contains nonliving things. Question: What is part of an ecological system?

waterfalls