question: What do sponges clean?
choices.text: animals matter crime water tissue retina skin mud
choices.label: A B C D E F G H
fact2: Since mussels are filter-feeders, they clean water as they feed.
combinedfact: sponges clean the water
formatted_question: What do sponges clean? (A) animals (B) matter (C) crime (D) water (E) tissue (F) retina (G) skin (H) mud