question: What cleans the water as it feeds?
choices.text: ecosystems sharks cats fish arachnids horses lamphreys sponges
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 as they feed
formatted_question: What cleans the water as it feeds? (A) ecosystems (B) sharks (C) cats (D) fish (E) arachnids (F) horses (G) lamphreys (H) sponges