question: what passes through materials at different speeds?
choices.text: waves vehicle flying animals mercury trucks silk Mohs
choices.label: A B C D E F G H
fact2: Sound, a type of energy, is produced by vibrations and travels in waves.
combinedfact: the type of material through which waves passes changes the speed at which waves move
formatted_question: what passes through materials at different speeds? (A) waves (B) vehicle (C) flying (D) animals (E) mercury (F) trucks (G) silk (H) Mohs