第6部分：完形填空
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
Where Did All the Ships Go?
The Bermuda Triangle （三角区） is one（1） the greatest mysteries of the sea. In this triangular area between Florida, Puerto Rico and Bermuda in Atlantic, ships and airplanes（2）to disappear more often than in （3） parts of the ocean. And they do so（4） leaving any sign of an accident or any dead bodies.
It is （5） 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 a wave 100 to 200-feet-high carried his ship about a mile away.
The most famous disappearance in the Bermuda Triangle was the US Naval （海军的） Air Flight 19. （6） December 5, 1945, five bomber planes carrying 14 men（7） 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（8） supernatural （超自然的）forces. It is suggested the（9） ships and planes were either transported to other times and places, kidnapped （绑架） by aliens'（外星人的） （10） attacked by sea creatures.
There are（11） natural explanations, though. The US Navy says that the Bermuda Triangle is one of two places on earth（12） a magnetic compass （指南针） points towards true north （13） magnetic north. （14）, planes and ships can lose their way if they don't make adjustments.
The area also has changing weather and is known（15） its high waves Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident.
