5. Crash-stop means an emergency_____ operation of the main engine(s) to avoid a collision. (A) release (B) return (C) revised (D) reversal

40. The symbol at Q3 means： (A) Light ship, with the mast visible at Chart datum (B) Wreck showing any part of hull or superstructure at the level of Chart Datum (C) Wreck, depth unknown, which is considered dangerous to surface navigation (D) Wreck, depth unknown, which is not considered dangerous to surface navigation