question: Navigation requires what?
choices.text: maps for travelling physical properties electricity calcium and protein electrical impulses hydration of cells trunks for packing electrical signals
choices.label: A B C D E F G H
formatted_question: Navigation requires what? (A) maps for travelling (B) physical properties (C) electricity (D) calcium and protein (E) electrical impulses (F) hydration of cells (G) trunks for packing (H) electrical signals