A、A water current struck his ship violently. B、A wave carried his ship far away. C、Great noise came down from the sky. D、Rough s

The Bermuda Triangle is one of the greatest mysteries of the sea In this triangular area between Florida, Puerto Rico and Bermuda in the Atlantic, ships and airplanes seem to disappear more often than in other parts of the ocean. And they do so without leaving any sign of an accident or any dead bodies. It is said that Christopher Columbus was the first person to record strange happenings in the area His compass stopped working, a flame came down from the sky, and [13]a wave 100 to 200 feet high carried his ship about a mile away. The most famous disappearance in the Bermuda Triangle was the U.S. Naval Air Flight 19. On December 5, 1945, five bomber planes carrying 14 men took off on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. The next morning, 242 planes and 19 ships took part in the largest air-sea search in history. But they found nothing. Some people blame the disappearances on supernatural forces. [14]It is suggested the missing ships and planes were either transported to other times and places, kidnapped by aliens or attacked by sea creatures. There are also natural explanations, though. The U.S. Navy says that the Bermuda triangle is one of two places on earth where a magnetic compass points towards true north instead of magnetic north. Therefore, planes and ships can lose their way if they don’t make adjustments. The area also has changing weather and is known for its high waves. [15]Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident.
13. What happened when Columbus sailed across the Bermuda Triangle?
14. Which assumption is not mentioned in the passage to explain the disappearances of ships and planes?
15. What’s the official explanation for the disappearances?